I have installed : "@angular/fire": "^18.0.1", Then i initializeApp in my app.config.ts : .... provideFirebaseApp(() => initializeApp(environment.firebaseConfig)), provideMessaging(() => getMessaging()), .... And then i try to listen to notifications in my app.component.ts : ngOnInit(): void { if(this.platform.isBrowser){ this.requestPermission(); this.listen(); } } requestPermission() { const messaging = getMessaging(); getToken(messaging, { vapidKey: environment.vapidKey }).then( (currentToken) => { if (currentToken) { console.log('Your token is: ', currentToken); } else { console.log('No registration token available. Request permission to generate one.'); } } ).catch((error) => { console.log('An error occurred while retrieving token. ', error.message); }) } listen() { const messaging = getMessaging(); onMessage(messaging, (payload) => { console.log('Message received. ', payload); this.message = payload; }) } And i get the following error - why ? : Firebase: No Firebase App '[DEFAULT]' has been created - call initializeApp() first (app/no-app). Continue reading...