I assumed all codes appear in the Rewards list, so I didn't bother to copy any codes when I completed the quests. Maybe that assumption was wrong, but it seems unlikely they would just flash a code at you once on a webpage without preserving it on the Rewards list or emailing it to you.as long as you received the codes after completing the quests, you should still be OK. Too bad they ran out of Pyre codes.
If I missed out, oh well. I was just curious if I was overlooking something, or if others had the same issue.