I am confused...

[Floortank]

You have to register the expansion separately from the early access. I know it's a bit confusing, but check your e-mail. You should have a mail from SE with a link to your registration code. Grab that, stick it in the mog station, and you're all set.

[Lizellea]

I have looked all over my email and I haven't gotten any registration code... at all. Also I don't use steam. I use the actual site if that helps.

[Floortank]

I have looked all over my email and I haven't gotten any registration code... at all. Also I don't use steam. I use the actual site if that helps.

The number is not in an e-mail. There is an e-mail that direct links you to the SE store, and if you log in it gives you the number. If you happen to be logged in already, it puts you right on the page with the serial number.

[Illmaeran]

I have looked all over my email and I haven't gotten any registration code... at all. Also I don't use steam. I use the actual site if that helps.

I didn't get one either, even after changing the email tied to my account. I had to go through the SE Store website to get the registration code for the full release version. It's "going around your ass to get to your elbow" and is a bit of a pain, but it'll get you what you need to be able to continue playing without interruption.