Help on referrals code adding

Help on referrals code adding

Hi

My domain name is

waranabank.com for which i need some mail accounts. I had received an referral invitation from one of my friend and created my email hosting. They have asked me to provide the referral code when i get signup but, I didnt get any suitable place to add those details.

Please help us where can i update the code so that we can avail the additional 5 free users as well as my friend.

Expecting your reply at the earliest.

Thanks
Balu