To remove the option for Pay What You Can (PWYC) pricing on a ticket, navigate to:
Events tab > 1. Click on the name of your event 2. Click Select then Tickets and Prices on the performance you'd like to change 3. Click the pencil icon under Actions to edit the ticket type 4. Uncheck the box for PWYC pricing 5. Click the disk under Actions to save the changes
If you have more than one performance, be sure to apply the changes to all performance dates by checking the box for Apply Prices To All Performances and clicking Apply Ticket Prices.