Using Firebase on Instant App on Android

Question

I'm working in migrating App to support Instant App.

So, I have modularized my project structure as follow

But when I'm adding Firebase, only firebase Analytics can works with it. Another feature like Firebase Auth, Storage, Firestore, And Database are not working in here.

I Got an Error :

Firebase App Not Initialized.
Although I have declared FirebaseApp.Initialize(this) through Activity 
or Application class.

But Firebase Analytic can works just fine.

Please help if anyone know how to solve this.

Answer 1

As you can see on this bug report there is a problem on the documentation and/or on the google service plugin. To resolve it you have to add the google-service.json and the apply plugin: 'com.google.gms.google-services code in every module and build.gradle file.