The way you’ve worded that is a bit confusing. The activation code should have been emailed to you, it’s included with the “Order Confirmation”.
There’s 3 different Steinberg-related accounts:
-The shop account, where you can download what you just purchased and resend receipts to your email (which include your activation code).
-The MySteinberg account, which is for managing your eLicensers, requesting official support and downloading the full installers for the versions of Cubase, Nuendo and Wavelab you own a license for. Registering Cubase or eLicenser registers it to your MySteinberg.
-The forum account, which is the one you used to post here.
They’re all completely separate from each other in order to give you more protection.