Is this the version of Rasa you were going for?
Also, I understand the pain of installing rasa on mac. What worked for me was using Python 3.7 instead (I used pyenv to set that up). I am not quite sure what it is with Python 3.9 that causes installation issues. If you don’t prefer Python 3.9 for any particular reason, then I wouldn’t recommend wasting time trying to figure out why this is happening and just downgrade to 3.7.