Gravity Forms has a Stripe add-on that allows you to charge your users at form submission using your Stripe.com account, but this add-on doesn’t support (currently) coupons created at your Stripe account.
Gravity Forms has a also its own Coupons add-on. Using this add-on you can create a workaround for the mentioned limitation of the Stripe add-on.
Basically we’re going to use the coupon at Stripe.com, a coupon created in the Gravity Forms Coupons add-on with the same name and discount, and a little snippet of code. Simply follow the steps below.