Firebase Cloud Messaging notification from Java instead of Firebase Console

Question

I am new to Firebase and I am running into errors such as mismatch sender id and Authentication Error with HTTP status 401 when my Java application tries to send a notificat

Answer 1

I was running into the same issue. The problem was in the line:

String serverKey = ;

This value should come from the Android app project; in this case it would be "My Notification Client" and not "My Notification Server".