AXIS License Plate Verifier

About the application

When installed on a compatible Axis camera, AXIS License Plate Verifier enables vehicles to access areas such as parking lots. The application reads the license plate captured by the camera and verifies it against an allowlist or blocklist stored in the camera.

Typical scenarios for AXIS License Plate Verifier:

Requirements

The application can be installed in compatible Axis network video devices that support AXIS Camera Application Platform. A complete list of compatible devices and firmware versions is available at axis.com/products/axis-license-plate-verifier/support-and-documentation

Find the device on the network

To find Axis devices on the network and assign them IP addresses in Windows®, use AXIS IP Utility or AXIS Device Manager. Both applications are free and can be downloaded from axis.com/support.

For more information about how to find and assign IP addresses, go to How to assign an IP address and access your device.

Browser support

You can use the device with the following browsers:

ChromeTM

Firefox®

EdgeTM

Safari®

Windows®

recommended

recommended

macOS®

recommended

recommended

Linux®

recommended

recommended

Other operating systems

✓*

*Supported in iOS and iPadOS

Access the device

  1. Open a browser and enter the IP address or host name of the Axis device.

    If you do not know the IP address, use AXIS IP Utility or AXIS Device Manager to find the device on the network.

  2. Enter the username and password. If you access the device for the first time, you must set the root password. See Set a new password for the root account.

  3. The live view page opens in your browser.

Set a new password for the root account

Important

The default administrator username is root. If the password for root is lost, reset the device to factory default settings. See Reset to factory default settings

Support tip: Password security confirmation check
  1. Type a password. Follow the instructions about secure passwords. See Secure passwords.

  2. Retype the password to confirm the spelling.

  3. Click Create login. The password has now been configured.

Secure passwords

Important

Axis devices send the initially set password in clear text over the network. To protect your device after the first login, set up a secure and encrypted HTTPS connection and then change the password.

The device password is the primary protection for your data and services. Axis devices do not impose a password policy as they may be used in various types of installations.

To protect your data we strongly recommend that you:

  • Use a password with at least 8 characters, preferably created by a password generator.

  • Don’t expose the password.

  • Change the password at a recurring interval, at least once a year.

Get started

Basic setup

  1. These setup instructions are valid for cameras that are not sold as a kit with AXIS License Plate Verifier
  2. Adjust the camera settings

  3. Install the application

These setup instructions are valid for all scenarios:

  1. Camera mounting recommendations

  2. Step-by-step guide

  3. Adjust the area of interest

  4. Select region

  5. Set up event storage

Adjust the camera settings

To access the camera settings, go to Find the device on the network.

  1. Place a vehicle in the area of interest.

  2. To make sure the license plate is big enough for the application to detect it, go to System > Orientation and select the pixel counter. Check that the width of the license plate equals at least 130 pixels for license plates with one row and at least 70 pixels for license plates with two rows.

  3. Go to the camera’s webpage, select the Image tab and do the following adjustments:

    • Set the autofocus area on the license plate and click Autofocus. If the license plate is still not in focus, fine-tune using the manual focus.

    • Turn off Wide dynamic range.

    • Set Local contrast to 20. This reduces noise during nighttime, but still lights up the license plates enough to make them visible. A higher local contrast value makes the license plates more visible during nighttime, but increases noise.

    • Set Max shutter to 1/500.

    • Set Max gain to 24 dB to optimize the blur and noise trade-off in most scenes. If the license plate gets overexposed, adjust the max gain down to 9 dB.

    • Turn off Lock aperture. This sets the iris to automatic mode, which we recommend especially if the vehicle faces direct sunlight.

  4. Test the above settings by running through the scenario with a vehicle. For best results, test the settings in the darkest lighting conditions. This way, you get a good result both during nighttime and daytime.

Install the application

Note

To install the application on the device, you need administrator rights.

  1. Go to the device’s webpage.

  2. Go to Settings > Apps.

  3. Click Add to upload the application file (.eap) to the camera.

  1. To activate the license, you need a license key that is generated by the license code and the Axis device serial number. If you don’t have a license key on the computer, do the following:
  2. Go to axis.com/applications

  3. Go to License key registration.

  4. Enter the license code and the serial number.

  5. Save the license key file on the computer. Browse to select the file and then click Activate.

Access the application settings

  1. In the camera’s webpage, go to Apps, start the application and click Open.

  1. Tabs
  2. Live view
  3. Latest event
  4. Event log

Camera mounting recommendations

  • When you select the mounting location, remember that direct sunlight can distort the image, for example, during sunrise and sunset.

  • The mounting height for a camera in a Access control scenario should be half of the distance of that between the vehicle and the camera.

  • The mounting height for camera in a Free flow (slow traffic license plate recognition) scenario should be less than half of the distance of that between the vehicle and the camera.

  • Access control capture distance: 2–7 m (6.6–23 ft). This example is based on the AXIS P3245–LVE-3 License Plate Verifier kit.
  • Capture distance: (x)Mounting height (y)
    2.0 m (6.6 ft)1.0 m (3.3 ft)
    3.0 m (9.8 ft)1.5 m (4.9 ft)
    4.0 m (13 ft)2.0 m (6.6 ft)
    5.0 m (16 ft)2.5 m (8.2 ft)
    7.0 m (23 ft)3.5 m (11 ft)
  • Free flow capture distance: 7–20m (23–65 ft). This example is based on the AXIS P1455–LE-3 License Plate Verifier kit.
  • Capture distance (x)Mounting height (y)
    7.0 m (23 ft)3.0 m (9.8 ft)
    10.0 m (33 ft)4.0 m (13 ft)
    15.0 m (49 ft)6.0 m (19.5 ft)
    20.0 m (65 ft)10.0 m (33 ft)
  • The camera’s mounting angle should not be larger than 30° in any direction.

  • Mounting angle from the side.
  • Mounting angle from above.
  • The image of the license plate should not tilt more than 5° horizontally. If the image is tilted more than 5°, we recommended that you adjust the camera so that the license plate is displayed horizontally in the live stream.

  • Horizontal tilt.

Step-by-step guide

When you first run the application, set up Free flow or Access control using the step-by-step guide. If you want to make changes later on, it can be found in the Settings tab under Configuration wizard.

Free flow

In Free flow, the application can detect and read license plates in slow speed traffic on larger access roads, city centers and enclosed areas like campuses, ports or airports. This allows for LPR-forensic search and LPR triggered events in a VMS.

  1. Select Free flow and click Next.

  2. Select the image rotation that corresponds to how your camera is mounted.

  3. Select the number of areas of interest. Note that one area can detect plates in both directions

  4. Select the region where the camera is located.

  5. Select capture type.

    • License plate crop saves only the license plate.

    • Vehicle crop saves the entire captured vehicle.

    • Frame downsized 480x270 saves the entire image and reduces the resolution to 480x270.

    • Full frame saves the entire image at full resolution.

  6. Drag the anchor points to adjust the area of interest. See Adjust the area of interest.

  7. Adjust the direction of the area of interest. Click the arrow and rotate to set the direction. The direction determines how the application registers vehicles entering or exiting the area.

  8. Click Next

  9. In the Protocol drop-down list, select one of the following protocols:

    • TCP

    • HTTP POST

  10. In the Server URL field, type the server address and port in the following format: 127.0.0.1:8080

  11. In the Device ID field, type the name of the device or leave as is.

  12. Under Event types, select one or more of the following options:

    • New means the first detection of a license plate.

    • Update is either a correction of a character on a previously detected license plate, or when a a direction is detected as the plate moves and is tracked across the image.

    • Lost is the last tracked event of the license plate before it exits the image. It also contains the direction of the license plate.

  13. To turn on the feature, select Send event data to server.

  14. To reduce bandwidth when using HTTP POST, you can select Do not to send images through HTTP POST.

  15. Click Next

  16. If you already have a list of registered plates, choose to import as either a blocklist or allowlist.

  17. Click Finish.

Access control

Use the setup wizard for quick and easy configuration. You can choose to Skip to leave the guide at any time.

  1. Select Access control and click Next.

  2. Select the type of access control to use:

  3. In the Barrier mode drop-down list, under Open from lists, select Allowlist.

  4. In the Vehicle direction drop-down list, select out.

  5. In the ROI drop-down-list, select the area of interest you would like to use, or if you would like to use all.

  6. Click Next

Image settings

  1. Select the number of areas of interest.

  2. Select the region where the camera is located.

  3. Select capture type. See Adjust the image capture settings.

  4. Drag the anchor points to adjust the area of interest. See Adjust the area of interest.

  5. Adjust the direction of the area of interest. The direction determines how the application registers vehicles entering or exiting the area.

  6. Click Next

Event data See Push event information to third-party software

  1. In the Protocol drop-down list, select one of the following protocols:

    • TCP

    • HTTP POST

  2. In the Server URL field, type the server address and port in the following format: 127.0.0.1:8080

  3. In the Device ID field, type the name of the device or leave as is.

  4. Under Event types, select one or more of the following options:

    • New means the first detection of a license plate.

    • Update is either a correction of a character on a previously detected license plate, or when a a direction is detected as the plate moves and is tracked across the image.

    • Lost is the last tracked event of the license plate before it exits the image. It also contains the direction of the license plate.

  5. To turn on the feature, select Send event data to server.

  6. To reduce bandwidth when using HTTP POST, you can select Do not to send images through HTTP POST.

  7. Click Next

  8. Import list from a .csv file.
  1. If you already have a list of registered plates, choose to import as either a blocklist or allowlist.

  2. Click Finish.

Adjust the area of interest

Note

If you move the area of interest more than 60º or if you place it outside the live view, it will automatically jump back to default position. Make sure the region of interest stays in position after you have saved the settings.

  1. Go to Settings .

  2. Click Edit area of interest.

  3. To adjust the area of interest, click anywhere in the area and drag the anchor points highlighted in blue.

  4. To get the correct direction feedback in the Event log, turn the arrow to the driving direction. Click outside the area of interest, and then click the arrow and rotate to set the direction. The direction feedback shows up in the Direction column. Note that one area can detect plates in both directions

  • To add a second of interest, select 2 in the Area of interest drop-down menu.

Example with one area of interest.
Note

For performance reasons, keep the area of interest as small as possible.

Select region

  1. Go to Settings > Image.

  2. In the Region drop-down list, select your region.

Adjust the image capture settings

  1. Go to Settings > Image.

  2. To change the resolution of captured images, go to Resolution

  3. To change the rotation of the captured image, go to Image rotation

  4. To change how you save your captured images, go to Save full frame:

    • License plate crop saves only the license plate.

    • Vehicle crop saves the entire captured vehicle.

    • Frame downsized 480x270 saves the entire image and reduces the resolution to 480x270.

    • Full frame saves the entire image at full resolution.

Set up event storage

This example use case explains how to store events of allowlisted license plate numbers for 30 days.

  • Requirements:
  • Camera physically installed and connected to the network.

  • AXIS License Plate Verifier up and running on the camera.

  1. Go to Settings > Events.

  2. Under Save events, select Allowlisted.

  3. Under Delete events after, select 30 days.

Additional settings

Add detected license plate to list

A license plate can be added directly to a list after being detected by the application.

  1. Click the Event log tab

  2. Go to Latest Event

  3. Click Add to list next to the license plate that you’d like to add.

  4. Select the list you would like to add the license plate in the list drop down menu.

  5. Click Append

Customize list names

You can change the name of any of the lists to fit your specific use case.

  • Go to List management

  • Go to the list menu of the list you want to change.

  • Select Rename

  • Type the name of the list.

The new list name will be updated in any existing configurations.

Import allowlisted license plate numbers

You can import allowlisted license plate numbers from a .csv file on the computer. In addition to the license plate number, you can also add comments for each license plate number in the .csv file.

The structure of the .csv file must look like this: license plate number, comment

Example

AXIS123, Reception1

AXIS345, Reception2

AXIS456, Reception3

  1. Go to List management

  2. Go to the context menu next to Allowlist and select Import from file.

  3. Browse to select a .csv file on the computer.

  4. Click OK.

  5. Check that the imported license plate numbers appear in the Allowlist.

Share license plate lists with other cameras

You can share the license plate lists with other cameras on the network. The synchronization will override all current license plate lists in the other cameras.

  1. Go to List management.

  2. Under Camera synchronization, type the IP address, username and password.

  3. Click +.

  4. Click Camera synchronization.

  5. Check that the date and time under Last sync updates accordingly.

Configure text overlay

A text overlay shows the following event information in the live view: weekday, month, time, year, license plate number.

  1. Go to Settings > Image.

  2. Activate Text overlay.

  3. Set Overlay duration to a value between 1 and 9 seconds.

  4. Select either date, time and license plate (Datetime + LP), or just the license plate (LP).

  5. Check that the overlay appears in the live view.

Detect license plates in low-light conditions

Each detection gets a score by the algorithm, this is called the sensitivity level (confidence parameter). Detections that have a lower score than the selected level will not show up in the list of events.

For scenes with low lighting you can lower the sensitivity level.

  1. Go to Settings > Detection parameters.

  2. Adjust the slider under Sensitivity level. To avoid false detections, we recommend that you lower the threshold value with 0.05 at a time.

  3. Check that the algorithm detects the license plates as expected.

Allow fewer characters on license plates

The application has a default minimum number of characters for a license plate to be detected. The default minimum number of characters is five. You can configure the application to detect license plates with fewer characters.

  1. Go to Settings > Detection parameters.

  2. In the Minimum number of characters field, type the minimum number of characters you want to allow.

  3. Check that the application detects license plates as expected.

Allow only exact matches of license plates

The matching algorithm automatically allows a deviation of one character when matching the detected license plate against the allowlist or blocklist. However, some scenarios need an exact match of all characters of the license plate.

  1. Go to Settings.

  2. Click Advanced settings.

  3. Select Strict matching.

  4. Click Save.

  5. Check that the application matches the license plates as expected.

Allow more than one character deviation when matching license plates

The matching algorithm automatically allows a deviation of one character when matching the detected license plate against the allowlist or blocklist. However, you can allow more than one character deviation.

  1. Go to Settings > Detection parameters.

  2. Under Allowed character deviation, select the number of characters that are allowed to be different.

  3. Check that the application matches the license plates as expected.

Set up secure connection

To protect communication and data between devices, for example between the camera and the door controller, set up a secure connection with HTTPS using certificates.

  1. Go to Settings > Security.

  2. Under HTTPS, Enable HTTPS.

  3. Select either Self-signed or CA-signed.

Note

Find out more about HTTPS and how to use it at axis.com/files/whitepaper/wp_hardening_guide_en_2006.pdf.

Vehicle entry and exit scenario

In the scenario for vehicle entry and exit, the application reads the vehicle license plate captured by the camera and verifies the license plate against a list of authorized or unauthorized license plate numbers stored in the camera.

This scenario requires the application embedded in a camera with I/O support or a connected I/O relay module to open and close the barrier.

Two possible setups for the vehicle entry and exit scenario.
  1. Axis camera with AXIS License Plate Verifier
  2. I/O communication
  3. Barrier
  4. Axis I/O relay module
  5. IP communication

Open a barrier for known vehicles using a relay module

This example use case explains how to set up AXIS License Plate Verifier together with a relay module to open a barrier for a known vehicle driving through a specific region of interest (ROI) into, let’s say a parking area.

  • Requirements:
  • Camera physically installed and connected to the network.

  • AXIS License Plate Verifier up and running on the camera.

  • Cables connected between the barrier and the relay module.

  • Basic setup done. See Basic setup.

  1. Go to the camera’s webpage, select Settings and open AXIS License Plate Verifier.

  2. Go to the relay module’s webpage and make sure the relay port is connected to the camera’s I/O port.

  3. Copy the relay module’s IP address.

  4. Go back to AXIS License Plate Verifier.

  5. Go to the Settings>Access control

  6. Go to Type and select Relay in the drop-down list.

  7. In the I/O output drop-down list, select the I/O port that is connected to the barrier.

  8. In the Barrier mode drop-down list, select Open from lists and then check Allowlist.

  9. In the Vehicle direction drop-down list, select in.

  10. In the ROI drop-down list, select the area of interest that covers the traffic lane.

  11. Enter the following information:

    • the IP address for the relay module in format 192.168.0.0

    • the username for the relay module

    • the password for the relay module

  12. To make sure the connection works, click Connect.

  13. To activate the connection, click Turn on integration.

  14. Go to the List management tab

  15. Enter the license plate number in the Allowlist field.

  16. Note

    The physical input ports 1 to 8 on the relay module correspond to ports 1 to 8 in the drop-down list. However, the relay ports 1 to 8 on the relay module correspond to ports 9 to 16 in the drop-down list. This is valid even if the relay module only has 8 ports.

  17. Check that the application identifies the license plate number in the allowlist as a known vehicle and that the barrier opens as expected.

Open a barrier for known vehicles using the camera's I/O

This example explains how to set up AXIS License Plate Verifier together with the camera’s I/O port to open a barrier for a known vehicle entering, for example, a parking area.

  • Requirements:
  • Camera physically installed and connected to the network.

  • AXIS License Plate Verifier up and running on the camera.

  • Cables connected between the barrier and the camera’s I/O port.

  • Basic setup done. See Basic setup.

Open a barrier for known vehicles using the camera's I/O
  1. Go to the application’s webpage and select the Event log tab and add detected license plates to a list. See Add detected license plate to list

  2. To edit the lists directly, go to the List management tab.

  3. Enter the authorized license plate numbers in the Allowlist field.

  4. Go to the Settings tab.

  5. Under Access control , select the Type drop-down list, select Internal I/O.

  6. Select the I/O output #.

  7. In the Barrier mode drop-down list, select Open from lists and then check Allowlist.

  8. In the Vehicle direction drop-down list, select in.

  9. In the ROI drop-down-list, select the area of interest you would like to use, or if you would like to use all.

  10. Check that the application identifies the license plate number in the allowlist as a known vehicle and that the barrier opens as expected.

Note

You can change the name of any of the lists to fit your specific use case.

Get notified about an unauthorized vehicle

This example explains how to set up the application so that an event that triggers a notification can be created in the camera.

  1. Go to List management.

  2. Enter the license plate number in the Blocklist field.

  3. Go to the camera’s webpage.

  4. Go to Settings > Events and set up an action rule with the application as a condition and with a notification as an action.

  5. Check that the application identifies the added license plate number as an unauthorized vehicle and that the action rule runs as expected.

Vehicle access control scenario

In the scenario for vehicle access control, the application can be connected to an Axis network door controller to configure access rules, create schedules for access times, and handle vehicle access not only for employees, but also, for example, visitors and suppliers.

For backup, use an access system involving a door controller and card reader. To set up the door controller and the card reader, see the user documentation at axis.com

  1. Axis camera with AXIS License Plate Verifier
  2. IP communication
  3. Axis network door controller with card reader
  4. I/O communication
  5. Barrier
  6. Optional third-party software

Connect to a door controller

In this example we connect the camera to a network door controller which means the camera works as a sensor. The camera forwards the information to the controller which in turn analyzes the information and triggers the events.

Note

When switching between the AXIS License Plate Verifier and AXIS Entry Manager, make sure to refresh the webpages to get access to all parameters.

  • Requirements:
  • Camera and door controller physically installed and connected to the network.

  • AXIS License Plate Verifier up and running on the camera.

  • Basic setup done. See Basic setup.

How to get the application up and running with AXIS A1001 Door Controller.
  1. Hardware configuration in AXIS Entry Manager
  2. Go to AXIS Entry Manager and start a new hardware configuration under Setup.

  3. In the hardware configuration, rename the network door controller to “Gate controller”.

  4. Click Next.

  5. In Configure locks connected to this controller, clear the Door monitor option.

  6. Click Next.

  7. In Configure readers connected to this controller, clear the Exit reader option.

  8. Click Finish.

  1. Configuration in AXIS License Plate Verifier
  2. Go the AXIS License Plate Verifier webpage.

  3. Go to the Settings>Access control

  4. Go to Type and select Controller in the drop-down list.

  5. Enter the following information:

    • the IP address for the controller in format 192.168.0.0

    • the username for the controller

    • the password for the controller

  6. Click Connect.

  7. If the connection is successful, “Gatecontroller” shows up in the Network Door Controller name drop-down list. Select “Gatecontroller”.

  8. In the Reader name drop-down list, select the reader connected to the door “Gatecontroller”, for example “Reader entrance”. These names can be changed in AXIS Entry Manager.

  9. To activate the connection, select Turn on integration.

  10. Enter one of the user’s license plate number in the test field and click Test integration. Check that the test was successful.

  1. Configure users, groups, doors, and schedules in AXIS Entry Manager
  2. Go to AXIS Entry Manager.

  3. Go to Access Management.

  4. Go to Doors > Add identification type.

  5. In the Credentials needed drop-down list, select License plate only.

  6. To set limits for when the identification type can be used, drag and drop a Schedule to the door.

  7. Add users and, for each user, add the credential License plate.

  8. Click Add credential again and enter the license plate information.

  9. Click Add new group and enter the information.

  10. To add users to a group, drag and drop Users to the user group.

  11. To give users access, drag and drop the Door to the user group.

  12. To limit the access time, drag and drop a Schedule to the user group.

  13. Overview of AXIS Entry Manager user interface.
    1. Users
    2. Doors
    3. Schedules
    4. User groups

Search for specific events

Use the search feature to search for events using a number of criteria.

  1. Go to the application’s webpage and select the Event log tab.

  2. Select the date in the Start time and End time calendar menus.

  3. Enter the license plate in the Plate field, if you want to search for a plate.

  4. Click the ROI drop down menu to select which region of interest, or if both should be relevant in the search.

  5. select Direction to filter by entry or exit.

  6. To filter out license plates that belong to either the allow- or blocklist, click the Access drop down menu.

  7. Click Search.

To go back to the live updated log, click Live.

Note

Once a search has completed you can se a brief summary of statistics pertaining to that search.

Export and share search results

To export any search result as a CSV file with the statistics at that time, click Export to save the results as a CSV file

To copy the API as a link which can be used to export data to third party systems, click Copy search link.

Integration

Push event information to third-party software

Note

The application sends the event information in JSON format. For more information, log in using your MyAxis account, go to the AXIS VAPIX Library and select AXIS License Plate Verifier

With this feature you can integrate third-party software by pushing the event data through TCP or HTTP POST.

  • Before you start:
  • The camera must be physically installed and connected to the network.

  • AXIS License Plate Verifier must up and running on the camera.

  1. Go to Integration > Push events.

  2. In the Protocol drop-down list, select one of the following protocols:

    • TCP

    • HTTP POST

  3. In the Server URL field, type the server address and port in the following format: 127.0.0.1:8080

  4. In the Device ID field, type the name of the device or leave as is.

  5. Under Event types, select one or more of the following options:

    • New means the first detection of a license plate.

    • Update is either a correction of a character on a previously detected license plate, or when a a direction is detected as the plate moves and is tracked across the image.

    • Lost is the last tracked event of the license plate before it exits the image. It also contains the direction of the license plate.

  6. To turn on the feature, select Send event data to server.

  7. To reduce bandwidth when using HTTP POST, you can select Do not to send images through HTTP POST.

  8. Click Save.

Send images of license plates to a server

With this feature you can push images of the license plates to a server through FTP.

  • Before you start:
  • The camera must be physically installed and connected to the network.

  • AXIS License Plate Verifier must up and running on the camera.

  1. Go to Integration > Push events.

  2. In the Protocol drop-down list, select FTP

  3. In the Server URL field, type the server address in the following format: ftp://10.21.65.77/LPR

  4. In the Device ID field, type the name of the device. A folder with this name will be created for the images. Images are created using the following format: timestamp_area of interest_direction_carID_license plate text_country.jpg

  5. Type the username and password for the FTP server.

  6. Under Event types, select one or more of the following options:

    • New means the first detection of a license plate.

    • Update is either a correction of a character on a previously detected license plate, or when a a direction is detected as the plate moves and is tracked across the image.

    • Lost is the last tracked event of the license plate before it exits the image. It also contains the direction of the license plate.

    • Note

      Direction is only included in the filename when Lost or Update is selected

  7. To turn on the feature, select Send event data to server.

  8. Click Save.

Note

Note that the image varies depending on what type of capture mode you have selected, see Adjust the image capture settings

Direct integration with 2N

This example describes direct integration with a 2N IP device

  1. Set up an account in your 2N device:
  2. Go to 2N IP Verso

  3. Go to Services > HTTP API > Account 1.

  4. Select Enable account.

  5. Select Camera access.

  6. Select License plate recognition.

  7. Copy the IP address.

  8. In the AXIS License Plate Verifier app:
  1. Go to Integration > Direct integration

  2. Add the IP address or URL to the 2N device.

  3. Select Connection type.

  4. Select what the Barrier is used for.

  5. Type your username and password.

  6. Click Enable integration.

  7. Click Save.

To check in the integration is working:

  1. Go to 2N IP Verso

  2. Go to Status > Events

Troubleshooting

Unknown vehicles are marked as accepted

If the application lets in vehicles with license plates that are not in the allowlist, one probable reason is that the comparison allows a deviation of one character.
For example, if AXI S1234 is in the allowlist the application accepts AXI SI234.
Similarly, if AXIS 1234 is in the allowlist the application accepts AXI 1234.

The connection between the application and controller or relay module doesn’t work

Make sure the controller, or relay module, allows data traffic through HTTP. To find out how to change this setting, go to the user manual for the corresponding device.