User fields (name, email, phone, address, city, country, zip) to be displayed on the confirmation form are normally set at global settings and valid throughout the website. If you want another set of fields to be filled by the client just on a particular page, however, you can choose them in the confirmation form shortcode, app_confirmation. You can omit, add fields and sort them as you wish.
In this example instead of default fields name, email, phone; email, name, postcode, city will be asked just on this page.
Note that this feature is especially powerful in conjunction with User Defined Fields Addon.