You can disable the replay of your event. This means that existing registrants, or new registrants will not be able to watch the event on demand.
Effectively making the webinar only accessible when it's live.
How to turn the replay off
Go into your event's settings, scroll down to advanced settings. In here, you'll find a toggle to turn your replay off:
Click save.
Repay off and registration page
If you have turned the replay off, the registration page remains available indicating that the event has ended. People cannot sign up to your on-demand webinar.