That has nothing to do with the browser. That is from the site itself. What it does if you accept or deny is up to the site to decide not for the forum to do that here.

This is not an element of the site. This is a GUI element from the Firefox program.

I think you can tap the Esc key to dismiss permission panels. But if they are too annoying, you can set Firefox to ignore sites' requests to send you notifications. The following article shows where to find that on the Settings page:

https://support.mozilla.org/en-US/kb/push-notifications-firefox#w_how-do-i-stop-firefox-asking-me-to-allow-notifications