To sell gift certificates for your Hyena Cart here are some options.

Use the Discount Codes feature in Hyena Cart

Stock your gift certificate for sale like a regular item in your Hyena Cart.  Just create a new listing and put it in whatever category you want and make the total price the amount you want to offer the gift certificate for.  Once it sells you will receive a notice and you can login, create your code and print off a certificate to mail, or zip an email, to the customer with the code.  Be sure you include in the listing if the customer will receive the code via email or if you will be snail mailing them a printed certificate.

To create your code, start by logging into your Vendor Pages and clicking “Discount Codes” to get to the discount page.  Now create a new discount code for the amount of the gift certificate.  If you want a single-use gift certificate, you might want to name the code something like CustomerName20 or Customer2389 — something not easy to guess but easy for you to identify.

Next,  you’ll want to either print a certificate and put the code and amount on it to be mailed to the customer, or type up an email to the customer with the information.  Include a note that when they want to redeem it they will put that code into the “Discount Code” box during checkout.  The amount will be automatically deducted from their total.

Now watch your order list and once you see that gift certificate has been redeemed, you’ll login to your Vendor Pages, click Discount Codes, and delete that code from your list so it can’t be used again.

Use the Gift Certificate Feature through PayPal

The other option is to use PayPal’s gift certificate feature.   Your customer can purchase a gift certificate, and PayPal holds the funds until the gift certificate is redeemed.

Details here: https://www.paypal.com/us/cgi-bin/webscr?cmd=xpt/Merchant/merchant/GCIntro