The Steam and Itch versions of the game are virtually identical, except for the differences in how Steam handles installation and execution. What exactly is the issue you encounter when you try to run the game via Steam?
I think newer macOS versions tend to have issue with RPG Maker MV games although I don't have a Mac, so I can't verify if even Apple Silicon Macs can run MV games. There is this post Regarding Future RPG Maker MV macOS Support that mentions that MV won't support macOS 11+. RPG Maker MZ games should work although Didnapper 2 is an MV game.
I don't know if MV games are 32-bit on Mac since they are on Windows (RPG Maker MZ is 64-bit only). I know it can be confusing if a Mac app is 32-bit and 64-bit. For example, Discord is 32-bit on Windows while the Mac version is 64-bit.