Order Payment Form with Coupon field integration?

Hi to all Sellers here,

I just want to know what's your favorite order payment form that can accept Paypal/Stripe payment and comes with coupon field integration?

I'm looking at JotForm and SPP, but Jotform did not specifically say about coupon integration. SPP is a little bit on pricey side, although I tested it before and loved the interface.

What are other options out there that you can recommend?

Thanks!