I got my first switchbot devices today and couldn’t get the integration to work either.
I found an article how you can use their API if you have a hub. Explaining how to get curtains in there. Which works pretty okay. Using that logic and the API documentation also got the switchbot itself in HA.
Or an article based on that topic
Does mean its now a cloud based integration and not locally. But its at least a work around I guess if you are really stuck with the official integration.