I'm wondering if using the server-sent events described here: https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events , therefore from a web browser on desktop or mobile, once the user "subscribe" to it, gets the notification even if the browser is closed.
I imagine that the popup window that sometimes I get browsing on some sites, like the one below
is given by adding the server-sent events, right?