I’ve got mullvad-vpn installed and it’s working fine. However in Ubuntu it has a padlock in the system tray so it’s easy to access the app and see at a glance if it’s connected. This does not seem to be present in NixOS? It may be that I’m missing a Gnome extension or something else which means that it does not display or maybe it’s just not there.
I did find the Gnome extension which gives some information when the applet panel is expanded but I was hoping for the same as I had in Ubuntu and even windows where there is a similar system tray item.