Spa Terrace access, Oceania Riviera?

We are sailing on Oceania Riviera's transatlantic cruise starting 3/28, first time on Oceania. We're in a concierge-level cabin & are wondering about access to the private Spa Terrace. Is it necessary to go to it immediately after boarding to register, or does our already-booked concierge cabin provide access, without any other action on our part?

Thanks to all for reading!

There is no registration. Your cabin card is all you need to enter and exit the area.