Invitation codes list only have one action
- Allow only the field value same as one of the code in the list that can submit form. The invitation code can only be used once.
View Invitation Codes List for Gravity Forms demo
Create Invitation Codes List and Add / Generate codes for it:
Make sure BSK Forms Blacklist enabled in Form settings
Apply Invitation Codes List to field
When submit form:
Purchase Gravity Forms Blacklist Pro