// Give the service worker access to Firebase Messaging. // Note that you can only use Firebase Messaging here, other Firebase libraries // are not available in the service worker. importScripts('https://www.gstatic.com/firebasejs/4.6.2/firebase-app.js') importScripts('https://www.gstatic.com/firebasejs/4.6.2/firebase-messaging.js') // Initialize the Firebase app in the service worker by passing in the // messagingSenderId. firebase.initializeApp({ 'messagingSenderId': '948017499394' }) // Retrieve an instance of Firebase Messaging so that it can handle background // messages. const messaging = firebase.messaging()