Hi there! I'm afraid I don't have a Steam Deck, but I can copy and paste what they told me on Reddit here.
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To Install on Steam Deck:
Go to Desktop mode, download the windows .zip, extract it to a folder of your choosing, add the .exe to Steam as None Steam Game, select the current Proton (7.06) or Proton-GE as the compatibility layer, and that is it already. Game starts fine!
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Let me know if you can do it. If you use Discord, there is a server I created some time ago: https://discord.gg/MtzRd732MQ
There have not been many discussions lately, but the members might be able to help you if you post a message.