When you registered, you chose an AffiliCon-ID. The AffiliCon-lD must consist of at least 4 characters, should not be more than 20 characters long and may only contain lower case letters. Only a minus (-) is allowed as a special character. The AffiliCon-lD is also your affiliate ID and is used to recognise and allocate your commissions and payouts. It appears in each of your affiliate and order form links and is therefore also visible to customers.
In your account you will find the AffiliCon-ID in the blue button at the top right (here: "demo-account-affilicon"):