Hello Alexis,
You must also register your UR28M’s serial number in your MySteinberg account. This will qualify you for the Cubase AI7 activation code inside your MySteinberg account and provide you with the 25 digit download access code and the 32 character activation code. If you have registered the hardware and already and downloaded AI7 but do not see the 32 character activation code, I would advise submitting a support request under MySupport in your MySteinberg account. In the support request please include your username and provide your serial number for the UR28M. From there a support agent can provide you with the needed information to update your license to Cubase AI7.