I have the same issue too. I have both Admin and Legal rights. I was able to produce promo codes for my apps up until the iTunes outage last week. Now the promo code link is no longer available on iTunes Connect.
Suspect it's related to the internal server relay issues Apply had last week. Links fail on iTunesConnect but I was able to work around it by going to my browser history to retrieve the links (i.e. the link to My App, User Roles, etc.)
However, I was not able to get the link for Promo Codes. Anyone able to help? The timing is really bad as we launched our new app just as the outage occurred, now we can't even run promotions as the codes are not available! One week on and it is still problematic.
Tried on:
Windows 7, Chrome
Macbook Air, OSX (10.8.3), Safari