Sorry, there's are no gift certificates available in the Esellerate system, you can buy a product to be gifted to someone, but you have to decided which product to buy and purchase it using the recipient data, except for the payment info.
It's not possible to just give an allowance that the recipient can use to purchase something on his own, basically because Esellerate doesn't keep user "accounts" with a balance open (like iTunes or Amazon, for example), which would be required to enable gift certificates.
