If you want to add sound to your notifications in the Laravel Panel,
look in the file: resources / views / layout / app.blade.php and look for line 197 in

[php]

messaging.onMessage (function (payload) and below: var notification = new Notification (notificationTitle, notificationOptions); add this: var audio = new Audio (‘{{asset (‘ sound / notification.mp3 ‘)}}’); audio.play ();

[/php]

remember to create the sound folder and add the .mp3 file