As Leo is a Python program, it should be distribution and operating system agnostic for anything that can run QT version 5 or 6, preferably 6 at this point, and has the Python bindings for QT among a few other dependencies.
I'm sure others have much more in-depth installation instructions than I would, since I have not used a Mac in a very long time, but the gist of it is you should have a newish version of Python 3, pyqt6, and any other needed modules/Python dependencies should make themselves known at runtime via exceptions.
You could potentially do something like Macports or Homebrew to get these dependencies and have a homogeneous working environment for open source non-mac-specific applications on your Mac.
Hope this gives you a start in the right direction!
Mike