Please configure this URL inside the PPC Control Panel >> Settings >> Global Engine Settings - Look for the setting reading: 'Link to your order processor form'
The way an advertiser will add funds to his/her account will be by purchasing credit from you. You need to set-up an order processing system. You may use any system you prefer. Companies such as PayPal and WorldPay offer e-commerce services for processing orders. Once you have set-up such an account and the appropriate pages you may enter the URL (Internet Address) in the settings section as explained above.
When a user clicks on the "Make Payment" tab in this Control Panel he will be directed to this page. Please contact PayPal or WorldPay if you need more information on being able to accept payments by credit card.