If you want to set a registration closing time for a Live event, go to Live > 1-1 Bookings/Live Class/Live Webinars/Live Interactive Webinars. Then create/edit a Live. On the Details tab of the corresponding Live, click Additional Settings.
You can set the Registration Condition here
Allow Registration Until the End of the Session
Close Registration [ ] Minutes/Hours/Days Before Event Start Time
Allow Registration Until the End of the Session
If this setting is enabled, individuals can register for the Live event without any time restrictions; registration will remain open until the event concludes.
Close Registration [ ] Minutes/Hours/Days Before Event Start Time
If you specify a time, registration will be closed to individuals attempting to register after the designated time.
Eg: If you enter 30 Minutes, people can register for the event half an hour prior to its scheduled start time.
Multiple Session:
In the case of Multiple Schedules, the same registration time limit applies to all schedules, and there is no possibility to set different registration availability times for each schedule. However, people can join the session using the direct join link.
Recurring session:
If the registration time limit is set, the time set is applicable to the first session of the recurring. To join the other sessions, people need to use the direct join link.