Firebase CLI

Create a Firebase project, then set up Google Application Default Credentials as described in Add the Firebase Admin SDK to your server. For CI/server use, the Firebase CLI docs recommend authenticating with ADC. In practice this usually means creating or selecting a Google Cloud service account with access to your Firebase project, downloading its JSON key or using your platform's workload identity flow, and pointing GOOGLE_APPLICATION_CREDENTIALS at the credential file or otherwise providing ADC.

On a machine with a browser, run firebase login:ci as documented in Firebase CLI reference. Visit the printed URL, sign in with your Google account, then store the returned token in FIREBASE_TOKEN for headless CI use. Firebase documents this as a legacy option and recommends Application Default Credentials instead.