JSFiddle - React, Tailwind, and code Playground

HTML

<button>Notifica</button>

JavaScript

function notifyMe() {
  if (!("Notification" in window)) {
    alert("This browser does not support desktop notification");
  }

  else if (Notification.permission === "granted") {
    var notification = sendNotification();
  }

  else if (Notification.permission !== 'denied') {
    Notification.requestPermission(function (permission) {

      if(!('permission' in Notification)) {
        Notification.permission = permission;
      }

      if (permission === "granted") {
        var notification = sendNotification();
      }
    });
  }
}


function sendNotification(){
    return new Notification( 
        "E' successo qualcosa!", { 
            icon: "http://www.sandropaganotti.com/wp-content/goodies/misc/official_me.small.png", 
            body: "Qui puoi mettere un dettaglio extra per descrivere l'evento" 
        }
    );
}

document.querySelector('button').addEventListener('click', function(){
    notifyMe();
});