importScripts("https://www.gstatic.com/firebasejs/9.10.0/firebase-app-compat.js"); importScripts("https://www.gstatic.com/firebasejs/9.10.0/firebase-messaging-compat.js"); // Initialize the Firebase app in the service worker by passing in the messagingSenderId. firebase.initializeApp({ apiKey: "...", authDomain: "...", databaseURL: "...", projectId: "...", storageBucket: "...", messagingSenderId: "...", appId: "...", }); // Retrieve an instance of Firebase Messaging so that it can handle background messages. const messaging = firebase.messaging();