https://protonvpn.com/support/official-linux-vpn-fedora/

Following this guide, an error will occur re the pgp during the install, it did for me. Make sure you run *both after the cli commands

sudo dnf check-update && sudo dnf upgrade

and

sudo dnf install --refresh proton-vpn-gnome-desktop 

You must accept the keys as outlined or it fails down the road. It never asked until running above code.

That did it for me. Good luck.