Hey! Sorry you’re running into issues. Pro Tools doesn’t support VST3 or CLAP. Unless you’re using a wrapper it definitely will not show up. I am looking into building an AAX version for Pro Tools user.
As for picking up system audio: that is only supported on macOS Ventura or newer. Apple only recently added support for that in Ventura: for alternative options see here: https://minimeters.app/help/audio-macos/
Let me know if you still have issues or questions.