GoAffPro provides you with the option to automatically apply discount codes for customers. When a customer visits your store using an affiliate's referral link, the coupon code assigned to the affiliate will automatically get applied at the checkout.
To automatically apply discount codes, go to the Coupons tab in the GoAffPro admin panel.
Here, enable the toggle in the Automatically apply discount section.
This will enable discount codes to get automatically applied at checkout for customers.