There are two user group settings, who can use this feature (for example only for users that already purchased something from you) and who can approve (mostly admin):
In the admin, Setup->Options->[UW] Affiliate Program you can set the referral key, commission percentage, minimum withdraw amount, results per page and also an option to show earned commissions in member stats:
Access to the affiliate program is in the front end:
A user can see Total earnings, wallet, his referral link and his referrals.
Admin account will see also withdraw requests, withdraw log and all affiliate commissions:
A notification is created when a new user registers using the referral:
Just go to the page Affiliate Program in your preferences and copy your referral link, place it wherever you like and you will get 10% from all sales from that link. This way you can earn all the money you had to pay for the add-ons.
❗NOTE❗ You have to be a customer first before you can use Affiliate Program.