Fix: Initialize Firebase App in firebase-messaging-sw.js

public/firebase-messaging-sw.js

@@ -4,7 +4,17 @@ try {
   importScripts(
     "https://www.gstatic.com/firebasejs/9.0.0/firebase-messaging-compat.js"
   );
-  // firebase.initializeApp(firebaseConfigObject);
+  var firebaseConfigObject = {
+    apiKey: "API_KEY",
+    authDomain: "PROJECT_ID.firebaseapp.com",
+    databaseURL: "https://DATABASE_NAME.firebaseio.com",
+    projectId: "PROJECT_ID",
+    storageBucket: "PROJECT_ID.appspot.com",
+    messagingSenderId: "SENDER_ID",
+    appId: "APP_ID",
+    measurementId: "G-MEASUREMENT_ID",
+  };
+  firebase.initializeApp(firebaseConfigObject);
 } catch (e) {
   importScripts("/__/firebase/7.15.0/firebase-app.js");
   importScripts("/__/firebase/7.15.0/firebase-messaging.js");
@@ -29,7 +39,7 @@ if (firebase.messaging.isSupported()) {
       image: payload.notification.image
     };
 
-    const promiseChain = clients
+    const promiseChain = self.clients
       .matchAll({
         type: "window",
         includeUncontrolled: true
@@ -41,7 +51,7 @@ if (firebase.messaging.isSupported()) {
         }
       })
       .then(() => {
-        return registration.showNotification(
+        return self.registration.showNotification(
           notificationTitle,
           notificationOptions
         );