If you’re looking for how to issue a promo code so a customer can use it while they sign up for a pre-paid service, head over here.
If you want to discount an order while you’re checking out a customer:
During checkout, click “Add discount”
Select from the list of discount codes that you have created
The discount code will be applied and then you can collect payment
💡 Need to create a discount code? Learn how to do that here