Error while registering to Backendless messaging for push notification

Android
1

Dear all,

I want to register my device to push notification
I done the neccery steps in Backendless and FireBase.

I using backendless 6.0.1

my method:
List channels = new ArrayList();
channels.add(“main”);
Backendless.Messaging.registerDevice(channels, new AsyncCallback() {
@Override
public void handleResponse(DeviceRegistrationResult response) {
Toast.makeText(context, “Device registered!”,
Toast.LENGTH_LONG).show();
Log.e(TAG, "handleResponse: "+response.getDeviceToken() );
}

        @Override
        public void handleFault(BackendlessFault fault) {
            Toast.makeText(context, "Error registering " + fault.getMessage(),
                    Toast.LENGTH_LONG).show();
            Log.e(TAG, "handleFault: "+fault.getMessage() );
        }
    });

but I getting error:
Could not deserialize server response: Attempt to invoke virtual method ‘byte[] java.lang.String.getBytes()’ on a null object reference

2

found the problem, error in api key. you can close it