GoAffPro provides you with the option to apply the coupon discount on each item in the customer's cart.
To apply the coupon discount on each item in the customer's cart, go to the Discounts section of the Shopify admin panel.
Here, click on the GOAFFPRO (App) coupon code.
This will open up the coupon code's settings page.
Now, select the "Fixed amount" option in the Types section.
After this, select the "Specific products" option in the Applies to section.
Now, uncheck the "Only apply discount once per order" box.
Finally, click on Save.