If you use an Arch-based distro, it's available in the Arch User Repository (AUR) [1]. With Aura [2], installation is as simple as:

    aura -A radarr

Yes, you need to use the CLI to run that, but it's trivial to do so and a real package management system brings many advantages over exe installers. The AUR, inspired by BSD's Ports, is one of the major advantages of Arch. It's very rare to find a package that isn't supported.

[1] - https://aur.archlinux.org/packages/radarr

[2] - https://github.com/fosskers/aura