If you run elite or invite only programs then you'll be able to use our program setting to require a password in order to register for a program. To set a program password, first go to your program's details by going to "Settings > Edit Details"
From your program's details, scroll down past the registration dates and you'll see an option for "Registration Password". Enter a password here and click save.
If your program has a registration password set, then your registrants will not be able to access registration unless they enter the correct password: