Necka (4/28/2021)
I'm going to create a separate post about this, because that's enough now with the lack of Unity support.
But just to reply to your question the workaround for you would be to create a project with the latest Unity 2019.4 LTS, import the Autosetup there, import your character, set it up to your liking and then just copy the whole folder that is setup to your unity 2020+ project.
Thanks for advice, I tought to try this way too.