I signed up for the free personal edition of Autodesk Fusion 360 to get started with 3d printing, and the first time I tried to launch it on macOS, it wouldn’t let me in because it refused to create a new team for me to join.

The solution ended up being to quit Fusion 360, open the Fusion Team Signup page in a browser, create a team there, then restart Fusion 360.

I found the solution in a forum post from 2019, so I’m not holding my breath waiting for Autodesk to fix it.