get device token firebase
//This is the only one worked for me as of August 29, 2021
FirebaseMessaging.getInstance().getToken().addOnSuccessListener(token -> {
if (!TextUtils.isEmpty(token)) {
Log.d(TAG, "token successfully retrieved : " + token);
} else{
Log.w(TAG, "token should not be null...");
}
}).addOnFailureListener(e -> {
//handle e
}).addOnCanceledListener(() -> {
//handle cancel
}).addOnCompleteListener(task -> Log.v(TAG, "This is the token : " + task.getResult()));