When you complete the payment on the gift card, you will immediately after receiving an order confirmation by email. In the order confirmation you will see a list of the things you bought. In addition to the gift card is a link to a pdf file on which stands a voucher code. It is this code that gift card recipient must use when buying.
You can either choose to print our copy of the gift certificate to you or you can be creative and make your own. It's just important that the code included.