Sync is on... What other devices do you have with Firefox? see screenshot I have several devices and running different versions of Firefox on most of them so that my data is not in just one place.

If sync is on now, you're logged in with nothing and this is the only device... You may be in trouble because what you have now is what will sync if this is the only device.

See:

• https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

If you use the Time Machine or other backup then try to restore the logins.json and key4.db file(s) from this backup.

• https://support.apple.com/guide/mac-help/restore-files-mh11422/mac