Add the rpm from protons website then rpm-ostree install package name.

This is one of the situations where layering packages is appropriate.

ProtonVPN is on Flathub, I’ve had no issues with it.

Edit: I’m an idiot and forgot kinoite is immutable.

Edit 2: Another option after the flatpak that @[email protected] mentioned, would be the nix package manager. This would be much more complicated than the flatpak, but if for some reason the flatpak didn’t work for you, this is another route you could take.

If you want the GUI app, you’ll need to add their repo. Instructions are here

It’s a gnome app so you’ll end up with some gnome dependencies with it.

Alternatively you could just use network manager in KDE. You’d need to log in to the protonvpn website and download configuration profile(s) for the connections you want to use and then add them in network manager. After that you should be able to connect from the network system tray icon.

Finally you could install the wireguard command lime tool with:

sudo dnf install wireguard-tools

You’ll still need to download (wireguard) configuration files from proton, and then add them to /etc/wireguard.

Once the configuration files are in the directory you can connect with:

sudo wg-quick up proton

Where proton is the name of the configuration file for the connection you want to use.

You can get it on Flathub. However as pointed out by other commenters, it is unofficial.

I have no solution, just wanted to point to this for further information gathering. Seems lot of people have this issue: https://discussion.fedoraproject.org/search?q=protonvpn. The official Linux installation guide for ProtonVPN is here, but I don’t think they cover Atomic systems: https://protonvpn.com/support/linux-vpn-setup/

I don’t use Fedora so I’m going to be one of those annoying people and not answer your question. However, I found the official UI to be awful and glitchy on Linux. I use Ubuntu with KDE Plasma and imported a few different Proton OpenVPN country configs into network manager and they work great. It’s possible to import wireguard config also, but IIRC there was a bit of fiddling with that.

If you don’t mind. You can try to setup proton VPN with network manager(which I am pretty sure have native WireGuard support). But I am not sure if you can do that with atomic OS or not tbh.