This blog shows you how to configure ACS with Azure Media Services AES/PlayReady license services with token authentication. The source code is listed here: https://github.com/AzureMediaServicesSamples/AES-Key-Delivery-with-ACS. Please download the source code in order to configure Key authorization policy.
1. Go to the Active Directory Tab in the Azure Management Portal
2. Click on Access Control Namespaces in options at the top of the page and click “+ New” and select Access Control -> Quick Create to create a new ACS Namespace. Read More here