Download and install BepInEx. I don't have idea what your game is 64bit or 323bit.
And Succubus Heaven is il2cpp processed.
BepInEx release site is
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. But, Those are for mono version. not for il2cpp.
Il2cpp version of BepInEx is released on
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. Visit and look site, you can find "#570" "#569" ...
Those are release version. Let me see... current latest version is #570. click "#570"
The game type of what I had is x64. May be same as you. Then use
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BepInEx Unity IL2CPP for Windows x64 games
If your game is 32bit, use
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BepInEx Unity IL2CPP for Windows x86 games
Download and extract to game folder(where SuccubusHeaven.exe exists)
Run game, First time run with BepInEx il2cpp version, takes minutes time.
Then BepInEx\Plugins folder would be created. If not match with x64/x32, "plugins" folder is not created.
Download
UniversalUnityDemosaics v1.4.2.6. You must use il2cpp version. ( DumbRendererDemosaicIl2Cpp.dll )
Put "DumbRendererDemosaicIl2Cpp.dll" file to BepInEx\plugins folder.
That's all. Now enjoy the game.