The Payment Registration Pro module allows you to configure many different custom fields to be displayed during the registration process. You can now use the Drag and Drop Form Builder to configure your custom fields.
To configure custom fields, navigate to the Registration module and select "Template Editor" from the admin menu:
In the demonstration video below, you can see the options for the custom fields within the Drag and Drop editor.
For more information on adding custom fields to your registration form click here.