So from what I have seen, here is what you can do....
How to use “Buy as Gift”
1. Simply login to your Z8Games account and click Deposit.
2. Click on "Prepaid Card" tab and Select any prepaid card as your payment method
3. Choose the amount of ZP you want to add and click on "Buy as Gift"
4. Select the game and Enter your friend's IGN(In Game Name)
5. Follow the instructions to complete your purchase.
Your friend will receive the ZP after the purchase is made.
-Courtesy of Z8Games.