text: importScripts("https://www.gstatic.com/firebasejs/7.16.1/firebase-app.js");
  importScripts(
      "https://www.gstatic.com/firebasejs/7.16.1/firebase-messaging.js",
  );
  // For an optimal experience using Cloud Messaging, also add the Firebase SDK for Analytics.
  importScripts(
      "https://www.gstatic.com/firebasejs/7.16.1/firebase-analytics.js",
  );
  
  // Initialize the Firebase app in the service worker by passing in the
  // messagingSenderId.
  firebase.initializeApp({
      messagingSenderId: "283896657842",
      apiKey: "AIzaSyDE-qXdbxDV9uv6ZMyf6nWgotOMGLr7f4A",
      projectId: "sandwichmap-f22d3",
      appId: "1:283896657842:web:6e52eaf48fd465308b56ab",
  });
  
  // Retrieve an instance of Firebase Messaging so that it can handle background
  // messages.
  const messaging = firebase.messaging();
  
  messaging.setBackgroundMessageHandler(function(payload) {
      console.log(
          "[firebase-messaging-sw.js] Received background message ",
          payload,
      );
      // Customize notification here
      const notificationTitle = "Background Message Title";
      const notificationOptions = {
          body: "Background Message body.",
          icon: "/itwonders-web-logo.png",
      };
  
      return self.registration.showNotification(
          notificationTitle,
          notificationOptions,
      );
  });