Proton-GE is a community build of Valve's Proton with extra compatibility patches (for games Valve's stock Proton struggles with). The easiest way to manage it - for Steam, Lutris or Heroic Games Launcher - is ProtonUp-Qt, distributed as a Flatpak.

pearOS NiceC0re (Arch-based)

Flatpak isn't installed by default here - set it up first:

sudo pacman -S flatpak
flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
flatpak install flathub net.davidotek.pupgui2

pearOS Goldwing (Debian-based)

Flatpak and the Flathub remote are already set up by default - just install it:

flatpak install flathub net.davidotek.pupgui2

On either build: open ProtonUp-Qt, pick Steam (or Lutris/Heroic), and install the latest GE-Proton build. Restart Steam, then select it for the game under Properties → Compatibility → Force the use of a specific Steam Play compatibility tool.