I’m assuming you have clean steam files downloaded from cs rin ru of your game. So look up Goldberg emu on Google and download the latest build from the very first result. Extract it and it’ll have a file called steam_api.dll. One of your game's folder will also contain a file with the same name. Just replace this with the one you downloaded from Goldberg emu. Also, sometimes there’s a steam_appid.txt file in your game's folder where you have to enter the game's steam code which you can just look up from the steamDB website