In the event dashboard, click on Registrations.

From the Sidebar click on "Setup Tickets"

This will take you to a page with the list of all tickets. Select the ticket you want to make private to click on "Edit"

Open the advanced section and ensure the “Is Private?” checkbox is checked.

Click save to persist your changes. Now you must set up the secret code which unlocks the private ticket. This makes the ticket private and will be visible to attendees upon entering a secret code.

From the sidebar, select “Setup Coupons”

This will take you to a page with a list of all coupons. Click on the “Create coupon code.”

Select “Access to Ticket Types” and click next. 

Enter the access code, select the private tickets to which this code gives access, and click save.

You can now share this access code with attendees who want to access these private tickets.

How to create private tickets which become accessible to the attendee upon entering a secret code?