Work or School Account Admin Approval
The AAD instance of B2C is trying to authenticate against your organization's tenant and needs permission to do so. Your AAD tenant's security settings need to be updated to allow access by the Microsoft Event app. Admin approval is a function of security setup by your organization's AAD tenant. Our team does not have insight into the implementation of this security feature or access to make changes to the setup.
Via the authentication process, Microsoft receives your first name, last name, and confirmed email. Microsoft uses this information to get an OID from Microsoft's AAD instance, to then use it to authenticate you into event tools.
To complete your registration, I recommend reaching out to the individual on your IT team who is responsible for managing the security settings for your AAD tenant to provide admin approval.
Alternatively, you may also use a Microsoft, LinkedIn, or GitHub account to register for this event. To do so, please select the applicable button from the registration sign in page.