Firebase FCM push, getting Error Missing Registration | Android

Question

I have seen this topic discussed before, but I think it\'s not the same scenario.

I\'m trying to send push notification from one device (going to be an admin device)

Answer 1

Thank you for posting your answer, anyway my codes works now, all I had to do is change the content-type (I have just copied from firebase docs the content-types )and send it to a subscribe topic.... now all my users can get the notification from my device :-).