In the Azure portal, navigate to App Registrations
Select the created app registration. If you can't find it, you probably don't have the right permissions. You can still find the app registration by changing the filter dropdown box to All apps.
Check the Owners of the selected app registration (application). If your not an owner, find an owner or a Global Administrator (you will need a Global Admin in the next steps).
Set the Required Permissions at least with the following Resource Access Windows Azure Active Directory (Microsoft.Azure.ActiveDirectory) with the application permission Manage apps that this app creates or owns and Read directory data. When you save this, this will result in the following array in the manifest: