Detect notification popup using JavaScript

I am creating userscript for messenger site I use. Is it possible to detect when site create notification pop up(usually on right bottom of screen) and get content of notification?

document.addEventListener('???', function(e) {  // when I get notification popup(get message)      // and get content of notification  });  

https://stackoverflow.com/questions/65589653/detect-notification-popup-using-javascript January 06, 2021 at 11:03AM