Why are my Android push notifications not working after migrating to the new Firebase Cloud Messaging (FCM) API?

If you have recently updated your Android application to use the new Firebase Cloud Messaging (FCM) API (V1) and notifications have stopped working, it is likely due to a configuration mismatch. Please follow these steps to ensure your setup is correct:

1. Upload Your Firebase Private Key: In your Pushwoosh Control Panel, navigate to your application's settings and select Configure Platforms for Android. You must upload the Firebase Private Key (a JSON file) obtained from your Firebase project. Crucially, ensure the old "Server Key" and "Sender ID" fields are empty, as they are not used with the new API.

2. Ensure Project Consistency: The google-services.json file included in your Android app's project files must correspond to the exact same Firebase project from which you generated the Firebase Private Key that you uploaded to Pushwoosh. Using credentials from two different Firebase projects will cause delivery to fail.

3. Enable the FCM API: Verify that the Firebase Cloud Messaging API is enabled in your Google Cloud Console for the correct project. You can check its status and enable it if necessary by visiting this link: https://console.cloud.google.com/apis/library/fcm.googleapis.com.

Following these three steps resolves the most common delivery issues after migrating to the new FCM API. It is also recommended to test notifications on a real physical device rather than an emulator for the most accurate results.