I'm on Ubuntu using Firefox browser. I get the notifications from reddit on my desktop. On the top toolbar, there is a bell icon where I can find unread notifications from telegram, firefox (from the sites allowed to send notifications), the package manager (about software updates) ...ect. Whenever someone replies to my post or comment on reddit a notification with sound appears on my desktop, and even if I miss it, I can see it if I click the bell icon on the top toolbar, which has a sign to indicate there is a notification I didn't click.
I'm setting permission for lemmy.dbzer0 to send notifications to "allowed" on Firefox, but I receive nothing. For instance I would forget to check replies to my posts and comments here. And it becomes even worst since I have an account in more than one lemmy instance, so I have to check every one of them for updates on discussions I missed!