If you are using Android 10 or higher, Android device ID is corrected instead of Wifi MAC address on the server.
You may be asked to provide Android device ID if you have 'This tablet is not able to use' message because, Android ID is a unique ID to identify your tablet.
Please download a third party app to identify Android device ID.
Here is the example app, which is Device ID, you can refer.
Then, share the screen shot of the abvoe.
If you can identify Android Device ID, you can use any third party app.