Consider the scenario. You have signed up for a 30 day Intune trial and it is now expiring (or expired). You want to move to production but you have already enrolled a lot of devices and do not want to start again. Therefore you buy Intune licenses through your Enterprise Agreement. You can now see a license key in your Microsoft Volume License Center.
But what do you do with this key? You cannot find anywhere in the Intune console to enter the key.
This is what you must do. Access the link below.
https://account.manage.microsoft.com/commerce/productkeystart.aspx
Log in using your trial subscription credentials and you will be able to add your license key.
Now log back in (or refresh) your Admin console and you will be good to go.
