How to make OBS chroma key smarter by using Background Replacement in macOS

If you want to use chroma key effect in a streaming or video conference app, but you can't get a physical green screen background in place, you can fake it. All by using Background Replacement in macOS.
You can do Chroma Key in OBS without a green screen, thanks to macOS.Whether it is streaming gameplay to Twitch or improving your Zoom calls, sometimes you want to replace the background with something else. It's unprofessional to have a background that includes piles of dirty clothes, random din