Cloud Sync not working (Dropbox)

I have updated my Mac to the latest version (BigSur 11.6) and also the latest Rekordbox version 6.5.3, but all the tracks are only stored in the computer and I cannot sync with the cloud. The option to sync is not highlighted, and if I go to Preferences>Library Sync> My Page, the option to login into Dropbox if off (all grey). Any ideas how to fix this?

I have checked and in the Mac privacy options, Dropbox is allowed to access all the files.