Settings Gift Voucher

hello i would like to offer gift vouchers like in this link http://demo.opencart.com/index.php?rout ... ut/voucher

can someone tell me where i can find the settings?
i know you can go to: sales > gift vouchers >
but what are the steps to configure the gift voucher like the link above? i want my customers to choose the amount themselve....

thank you in advance.

nevermind, i found it in the footer..