Use referral code at registration
The referral code has to be inserted during the registration process. Make sure to enter it in the designated "Referral Code" field before completing your registration.
Make sure to enter the referral code during registration.
Once you are registered, you will not be able to enter the referral code anymore.
Your referral code is your Wickie username. Click on your name at the top right and you'll find it under your name (e.g. @wickietag).