Discounts are set up under Shop, then Discounts. A code you create can be applied by a buyer at checkout.
- Give the code something short and sayable — people type these on phones.
- Set what it takes off and what it applies to.
- Give it an end date if it is tied to a campaign, so it stops on its own.
A discount changes the total the buyer is told to pay. Since the buyer pays you directly, it is on you to charge the discounted amount — nothing collects it for you.