1) Press Windows Key + E
2) At the top type [%LOCALAPPDATA%\Dawnwalker\Saved\Config\
3) Click Windows Folder
4) Open GameUserSettings.ini
5) Change
bUseHDRDisplayOutput=True
HDRDisplayOutputNits=1000
6) Save the file. Then right click it —> properties —> Read only.
HDR should work now.