How I install Mullvad on Silverblue based distros and add repos
One of the things I struggled with initailly when using immutables was installing programs like VPNS that need to interact with the immutable parts of the distro but don't have a flatpak option. I figured I'd just make a post to help anyone with this specific issue regarding mullvad or if it helps people install other software they need.
I don't know anything about immutable distros, but any good VPN provide Wireguard or OpenVPN config that you can just import into your network settings/manager. Mullvad does.