In order to restrict the event:
Step 1: Enable Restrict Access
Open dashboard > event > settings
Login Option > Toggle On the Restrict Access button
Step 2: Set Login Via:
Here you can set - how do you want attendees/speaker/booth members to join the event.
(A) System Generated Code: With this option, a system-generated code will be sent to the user email id, whenever they log in to your event platform.
This would be a random system-generated 4 digit code and it will be sent to the user every time, they log in to your event platform.
(B) Custom Login Code: With this option, you can set a custom code for all users & it would remain same throughout your event. This code will be sent to the users, whenever they log in to your event platform.
You can either have a unique code for each user or set the same code for all, this functionality can be controlled and managed at your end.