Select Direct Payment methods from the Payment Gateways page.
In the Create Listing page, scroll down to Payment Methods to see available (not all available methods are also enabled - see below) Direct Payment methods:
To enable WorldPay select it, check the Click here box, and complete the credentials menu:
Confirmation screen:
Complete Direct Payment info (one-time process) from the Account Settings (Home -> Members Area -> My Account -> Account Settings) menu: