Whenever I launch BTT, click any of the sync setting (enable, reset, etc) I get a popup that says I need to log into icloud in order to use sync. I definitely am logged into icloud.
Catalina: 10.15.1 (19B2106)
BTT: 3.214
Any solution to this?
Same problem here since updated to Catalina. I'm on 10.15.7 and tried it with lots if different BTT versions. Even last one 3.560.
Is there a problem concerning rights to access icloud? BTT doesn't show up under Preferences -> Accounts -> iCloud -> iCloud Drive (Options...).
I know it actually does show up there on High Sierra.
..had the same issue - then I noticed that while I was indeed logged into iCloud, iCloud Drive was not activated - checking the box here solved the issue for me 
I'm having this same issue. No matter whether I reset sync or delete cloud data, I'm told that I need to login to iCloud to use sync. Yet I am logged in.