Not every Linux desktop environment comes out with support for tray icons, the most infamous one for that being GNOME, one of the most popular desktop environments. Since GNOME 44, it focuses on a "Background apps" feature, which uses xdg-desktop-portal to find apps running in the background, with the ability to show them.

Personally, I must say I like that feature, and would like to avoid installing extensions adding back the tray. At the same time, I'd love it if the Proton VPN was able to start minimized on login in my prefered DE, especially since it's possible for other applications (such as Geary, for example).

Thank you for considering this feature request, and I apologize if i pointed to incorrect APIs for the task.