Seripa is sold on its own, so it needs its own licence even if you own Listn Studio.
The first time Seripa opens, a 14 day trial starts and everything works. Open Seripa's Settings: the top line says how many days are left, like Trial, 5 days left.
When the trial ends, Seripa goes quiet and shows Seripa needs a licence to play, with three buttons:
Your sessions and sounds are all still there.
Listn Hub puts it on this computer. Settings then says Licensed to and your email. Seripa works offline after that.