How To Install

Install by add directly in manifest.json in folder Packages/manifest.json

for version 12.1.0

"com.google.firebase.messaging": "https://github.com/firebase-unity/firebase-messaging.git#12.1.0",

dependency firebase-app 12.1.0, external-dependency-manager 1.2.177

"com.google.firebase.app": "https://github.com/firebase-unity/firebase-app.git#12.1.0",
"com.google.external-dependency-manager": "https://github.com/google-unity/external-dependency-manager.git#1.2.177",