the code should be in the link from the "Your Oculus order" email you got. ___________
Hi XXX,
You can use this link to access your order information.
If you have any questions, don’t hesitate to contact Oculus Support.
- The Oculus Team
Need Help? Oculus Support Center
____________
In there is the link pointing to your order you made while in that "anonymous"/temporary account. That link will bring you to your order. the link expires, so an new email will be sent to you if you access the link if the link got expired, with the same email content and with a working link...
In that page you will see the code, last item in the order. copy it and paste it in the Oculus Rift app, under Settings, Redeem Code, using your real account which you were instructed to create when you started the oculus app the first time.