From your firebase admin please click Add Firebase to your Android app like this picture :
1. go to : https://console.firebase.google.com/ and login to your google account.
In this article I will show you what you need to prepare to implement Google analytics to your android App.
1. PREPARE API_KEY
For android developer package name is very important, because its the identifier for their application. Rename package on android studio is no longer difficult. But here we provide brief step to rename package :
Obtain Server API_KEY for notification:
Then go to Project Settings -> Cloud Messaging, and get the new updated API Key.
OK Finish All you need for implement GCM is here :
GOOGLE_API (server) or Server key : AIzaSyB34PW……..
Use same firebase project if you want to generate file google-services.json for android