To be able to define prices of tickets to the center we will go to:
Customers → General Rates → Vouchers → Access Vouchers
Once inside the access vouchers window, we will have the list of all the bonds we have, if we want to modify or define prices of one of those bonds click on the "Edit" green icon.
Within the voucher tab, we will go to the Prices option on the left menu, and click on the "Edit" button.
From here, we can see and edit the Amount option.