android/src/main/java/com/hoxfon/react/RNTwilioVoice/TwilioVoiceModule.java
/*
     * Register your FCM token with Twilio to receive incoming call invites
     *
     * If a valid google-services.json has not been provided or the FirebaseInstanceId has not been
     * initialized the fcmToken will be null.
     *
     * In the case where the FirebaseInstanceId has not yet been initialized the
     * VoiceFirebaseInstanceIDService.onTokenRefresh should result in a LocalBroadcast to this
     * activity which will attempt registerForCallInvites again.
     *
     */
Register your FCM token with Twilio to receive incoming call invites
If a valid google-services.json has not been provided or the FirebaseInstanceId has not been
initialized the fcmToken will be null.

In the case where the FirebaseInstanceId has not yet been initialized the
VoiceFirebaseInstanceIDService.onTokenRefresh should result in a LocalBroadcast to this
activity which will attempt registerForCallInvites again.
Register your FCM token with Twilio to receive incoming call invites If a valid google - services . json has not been provided or the FirebaseInstanceId has not been initialized the fcmToken will be null . In the case where the FirebaseInstanceId has not yet been initialized the VoiceFirebaseInstanceIDService . onTokenRefresh should result in a LocalBroadcast to this activity which will attempt registerForCallInvites again .
private void registerForCallInvites() {
        FirebaseApp.initializeApp(getReactApplicationContext());
        final String fcmToken = FirebaseInstanceId.getInstance().getToken();
        if (fcmToken != null) {
            if (BuildConfig.DEBUG) {
                Log.d(TAG, "Registering with FCM");
            }
            Voice.register(getReactApplicationContext(), accessToken, Voice.RegistrationChannel.FCM, fcmToken, registrationListener);
        }
    }
private void registerForCallInvites ( ) { FirebaseApp . initializeApp ( getReactApplicationContext ( ) ) ; final String fcmToken = FirebaseInstanceId . getInstance ( ) . getToken ( ) ; if ( fcmToken != null ) { if ( BuildConfig . DEBUG ) { Log . d ( TAG , "Registering with FCM" ) ; } Voice . register ( getReactApplicationContext ( ) , accessToken , Voice . RegistrationChannel . FCM , fcmToken , registrationListener ) ; } }
Register your FCM token with Twilio to receive incoming call invites
 If a valid google-services.json has not been provided or the FirebaseInstanceId has not been
 initialized the fcmToken will be null.
Register your FCM token with Twilio to receive incoming call invites If a valid google - services . json has not been provided or the FirebaseInstanceId has not been initialized the fcmToken will be null .