Uruchom exe w prefiks Proton
cd /path/to/steam/steamapps/compatdata/20920/pfx
STEAM_COMPAT_DATA_PATH="/path/to/steam/steamapps/compatdata/20920" WINEPREFIX=$PWD \
"$HOME/.steam/root/steamapps/common/Proton 5.0/proton" run ./drive_c/path/to/custom_application.exe
Misty Magpie