[Android] Fcm support Default FirebaseApp is not initialized in this process

August 26, 2020

This project migrated from GCM to Firebase and you need to perform these steps:

Setup Firebase following the 4 steps of Option 1.
You will get a file calledgoogle-services.jsonto add to yourandroid/appfolder =>android/app/google-services.json.
In step 4, you addedimplementation 'com.google.firebase:firebase-core:16.0.8', replace it withimplementation "com.google.firebase:firebase-messaging:17.3.0"instead.

Your setup should looks now like:

package.json

...
  "dependencies": {
...
    "react-native-notifications": "^1.5.0",
...

build.gradle

...
buildscript {
...
    dependencies {
...
        classpath 'com.google.gms:google-services:4.2.0'
...

app/build.gradle

...
dependencies {
    ...
    implementation "com.google.firebase:firebase-messaging:17.3.0"
    ...
}
...
apply plugin: 'com.google.gms.google-services'