add the game to steam ,'add non-steam game', then in steam go to Deeper Club's settings under compatibility click the 'force use of specific Steam Play compatibility tool'. this should let you use proton, however i am running into a suspected bug with proton where the money value is not increasing and is set to 0 after day 1. testing proton versions, will update if i find a solution, I am full of the big dumb and expected the 'rent' number to go up. >~<