Described by https://forum.kicad.info/t/presenting-padne-a-tool-for-dc-power-delivery-network-analysis/64966/9
The main issue is that KiCad on MacOS is bundled with old Python and pcbnew.py cannot be imported externally: https://kigadgets.readthedocs.io/en/latest/getting_started/macos_workaround.html
Probably the best way would be to bundle it using pyinstaller like on Linux?