I know I'm super late on this but for you or anyone else interested in running this with UnityModManager try using the Assembly installation method instead of the DoorstopProxy With UnityModManager, it worked for me.
When you open Unity Mod Manager, after you select the game and then the game location, the last thing listed is Installation method. The choices are DoorstopProxy -or- Assembly. Select Assembly and then try installing this BepInEx mod.
how to integrate with unitymodmanager (5 comments)
how can this mod be used while using UnityModManager ?