Messaging: The notification permission was not granted and blocked instead

Question

Firebase messaging error in https server.

An error occurred while retrieving token. FirebaseError: Messaging: The notification permission was not granted and blocked instead. (messaging/permission-blocked).

What should I do to get my token? On localhost, it's working.

Here is my code:

firebase-messaging-sw.js

// Import and configure the Firebase SDK
// These scripts are made available when the app is served or deployed on Firebase Hosting
// If you do not serve/host your project using Firebase Hosting see https://firebase.google.com/docs/web/setup
importScripts("https://www.gstatic.com/firebasejs/7.8.1/firebase-app.js")
importScripts("https://www.gstatic.com/firebasejs/7.8.1/firebase-messaging.js")


// Your web app's Firebase configuration
var firebaseConfig = {
  apiKey: apiKey,
  authDomain: authDomain,
  databaseURL: databaseURL,
  projectId: projectId,
  storageBucket: storageBucket,
  messagingSenderId: messagingSenderId,
  appId: appId,
  measurementId: measurementId
};


// Initialize Firebase
firebase.initializeApp(firebaseConfig);

const messaging = firebase.messaging();
/**
 * Here is is the code snippet to initialize Firebase Messaging in the Service
 * Worker when your app is not hosted on Firebase Hosting.
 // [START initialize_firebase_in_sw]
 // 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/4.8.1/firebase-app.js');
 importScripts('https://www.gstatic.com/firebasejs/4.8.1/firebase-messaging.js');
 // Initialize the Firebase app in the service worker by passing in the
 // messagingSenderId.
 firebase.initializeApp({
   'messagingSenderId': 'YOUR-SENDER-ID'
 });
 // Retrieve an instance of Firebase Messaging so that it can handle background
 // messages.
 const messaging = firebase.messaging();
 // [END initialize_firebase_in_sw]
 **/

// If you would like to customize notifications that are received in the
// background (Web app is closed or not in browser focus) then you should
// implement this optional method.
// [START background_handler]

// [END background_handler]

messaging.setBackgroundMessageHandler(function(payload) {
  console.log('[firebase-messaging-sw.js] Received background message ', payload);
  // Customize notification here
  var notificationTitle = 'Background Message Title';
  var notificationOptions = {
    body: 'Background Message body.',
    icon: '/firebase-logo.png'
  };

  return self.registration.showNotification(notificationTitle,
    notificationOptions);
});

footer.blade.php in //script// section:

  // Your web app's Firebase configuration
  var firebaseConfig = {
     apiKey: apiKey,
  authDomain: authDomain,
  databaseURL: databaseURL,
  projectId: projectId,
  storageBucket: storageBucket,
  messagingSenderId: messagingSenderId,
  appId: appId,
  measurementId: measurementId
  };

  // Initialize Firebase
  firebase.initializeApp(firebaseConfig);

  const tokenDivId = 'token_div';
  const permissionDivId = 'permission_div';

  const messaging = firebase.messaging();

  messaging.usePublicVapidKey('BKotWNDl7JOuYb-UeusSlSl47onAFH9sWJ_M1WDivsjWq0AZWah5LjVfBAxbcS8T8Yo10HEw_xPX68kMnzTQC2k');

  // Get Instance ID token. Initially this makes a network call, once retrieved
  // subsequent calls to getToken will return from cache.
  messaging.getToken().then((currentToken) => {
    if (currentToken) {

      sendTokenToServer(currentToken);
      updateUIForPushEnabled(currentToken);
    } else {
      // Show permission request.
      console.log('No Instance ID token available. Request permission to generate one.');
      // Show permission UI.
      updateUIForPushPermissionRequired();
      setTokenSentToServer(false);
    }
  }).catch((err) => {
    console.log('An error occurred while retrieving token. ', err);
    showToken('Error retrieving Instance ID token. ', err);
    setTokenSentToServer(false);
  });

  // Callback fired if Instance ID token is updated.
  messaging.onTokenRefresh(() => {
    messaging.getToken().then((refreshedToken) => {
      console.log('Token refreshed.');
      // Indicate that the new Instance ID token has not yet been sent to the
      // app server.
      setTokenSentToServer(false);
      // Send Instance ID token to app server.
      sendTokenToServer(refreshedToken);
      // ...
    }).catch((err) => {
      console.log('Unable to retrieve refreshed token ', err);
      showToken('Unable to retrieve refreshed token ', err);
    });
  });

  function resetUI() {
    clearMessages();
    showToken('loading...');
    // [START get_token]
    // Get Instance ID token. Initially this makes a network call, once retrieved
    // subsequent calls to getToken will return from cache.
    messaging.getToken().then(function(currentToken) {
      if (currentToken) {
        sendTokenToServer(currentToken);
        updateUIForPushEnabled(currentToken);
      } else {
        // Show permission request.
        console.log('No Instance ID token available. Request permission to generate one.');
        // Show permission UI.
        updateUIForPushPermissionRequired();
        setTokenSentToServer(false);
      }
    }).catch(function(err) {
      console.log('An error occurred while retrieving token. ', err);
      showToken('Error retrieving Instance ID token. ', err);
      setTokenSentToServer(false);
    });
    // [END get_token]


  }


  function showToken(currentToken) {
    // Show token in console and UI.
    var tokenElement = document.querySelector('#token');
    tokenElement.textContent = currentToken;
  }

  // Send the Instance ID token your application server, so that it can:
  // - send messages back to this app
  // - subscribe/unsubscribe the token from topics
  function sendTokenToServer(currentToken) {
    if (!isTokenSentToServer()) {
      console.log('Sending token to server...');
      // TODO(developer): Send the current token to your server.
      setTokenSentToServer(true);
    } else {
      console.log('Token already sent to server so won\'t send it again ' +
          'unless it changes');
    }

  }

  function isTokenSentToServer() {
    return window.localStorage.getItem('sentToServer') === '1';
  }

  function setTokenSentToServer(sent) {
    window.localStorage.setItem('sentToServer', sent ? '1' : '0');
  }

  function showHideDiv(divId, show) {
    const div = document.querySelector('#' + divId);
  }

  function requestPermission() {
    console.log('Requesting permission...');
    // [START request_permission]
    messaging.requestPermission().then(function() {
      console.log('Notification permission granted.');
      // TODO(developer): Retrieve an Instance ID token for use with FCM.
      // [START_EXCLUDE]
      // In many cases once an app has been granted notification permission, it
      // should update its UI reflecting this.
      resetUI();
      // [END_EXCLUDE]
    }).catch(function(err) {
      console.log('Unable to get permission to notify.', err);
    });
    // [END request_permission]
  }

  function deleteToken() {
    // Delete Instance ID token.
    // [START delete_token]
    messaging.getToken().then(function(currentToken) {
      messaging.deleteToken(currentToken).then(function() {
        console.log('Token deleted.');
        setTokenSentToServer(false);
        // [START_EXCLUDE]
        // Once token is deleted update UI.
        resetUI();
        // [END_EXCLUDE]
      }).catch(function(err) {
        console.log('Unable to delete token. ', err);
      });
      // [END delete_token]
    }).catch(function(err) {
      console.log('Error retrieving Instance ID token. ', err);
      showToken('Error retrieving Instance ID token. ', err);
    });

  }

  // Add a message to the messages element.
  function appendMessage(payload) {
    const messagesElement = document.querySelector('#messages');
    const dataHeaderELement = document.createElement('h5');
    const dataElement = document.createElement('pre');
    dataElement.style = 'overflow-x:hidden;';
    dataHeaderELement.textContent = 'Received message:';
    dataElement.textContent = JSON.stringify(payload, null, 2);
    messagesElement.appendChild(dataHeaderELement);
    messagesElement.appendChild(dataElement);
  }

  // Clear the messages element of all children.
  function clearMessages() {
    const messagesElement = document.querySelector('#messages');
    while (messagesElement.hasChildNodes()) {
      messagesElement.removeChild(messagesElement.lastChild);
    }
  }

  function updateUIForPushEnabled(currentToken) {
    showHideDiv(tokenDivId, true);
    showHideDiv(permissionDivId, false);
    showToken(currentToken);
  }

  function updateUIForPushPermissionRequired() {
    showHideDiv(tokenDivId, false);
    showHideDiv(permissionDivId, true);
  }

Answer 1

This indicates that you have blocked the push notifications permission on the deployed website. It's messaging.getToken() that is likely erroring out (see the docs for more).

If you're using Chrome, you should be able to click the lock to the left of the URL and go to "Site Settings" where you'll see a bell icon with the notification settings for the site:

This may be set to "Block" and you would need to change it to "Allow" instead.

Answer 2

Make sure you're not in an incognito tab - in that case the permissions dialog (Allow/Block) won't show up (in Chrome at least)