I play a Steam version but if you have Steam you go to the Games Library > FFXIV : ARR and there will be a menu to the right. In that menu is "CD Key", you want the pre purchase one.

I didn't get any emails at all about this, I had to figure it out.

Edit: Oh, you're talking about playing beyond early access. I don't see any reason they'd block us from standard launch but if they do there should be a "standard" key too