How do you create a "promo code" for an iPhone app

How you do you "create promo codes" for an app as given in the answer by David Maymudes (below question link)? Is there an iOS UI for it?

开发者_开发百科

How to restrict application distribution to a group of users only via Apple AppStore?

---

Go to itunesconnect.apple.com. On the front page is a link to "Request Promotional Codes".

---

You register as a developer and do it through "iTunes Connect", option "Request Promotional Codes"