title: How to give a 100% discount in Stripe for one-time payments and to some, not all, users? And how to integrate a discount input box into Stripe popup?
body: <p>I process payments via Stripe on my website. To some users, I want to give a 100% discount to my products. And also I want to test the payment process myself in the <strong>live mode</strong>, with the live keys, right on my production server, and that means that a 100% discount will come in handy for me too. </p>
  
  <p>Is this possible? How?</p>
  
  <p>P.S.
  It's not a subscription, but a one-time payment.</p>