This article covers MoonClerk's new dashboard design. If your account still uses the classic design, see the classic version of this article.
While you are creating a new payment form or editing an existing one, you will have the option to enable coupons to be used.
1) In the builder, scroll down to the Add-ons section, click its row to expand it, and then click Coupons.
2) Turn on "Let payers enter a coupon code." The checkout preview immediately shows the Coupon Code field your payers will see.
3) Click Save at the top of the page, then click Publish to make the change live for your payers. On a live form, saved changes stay unpublished — and invisible to payers — until you publish them. Now, when a payer is checking out, they will have the option of applying a coupon code.