Well it's no use. Apparently the registration program was for a limited time only and they have ended it so they can do testing. The full official release of Android 10 wont be for another 2-3 weeks.
You'll be waiting a while. Samsung is notoriously SLOW with updates (unless you're talking about joining the beta program). I wouldn't expect an update to Android 10 before February, but even then they may not do it until after the S11 launches (in a misguided attempt to not.stealnits thunder).