In new Azure Portal i don't see any way to manage AD. Customer does not really have Azure AD subscription just Office 365. But i can see it in old Management, add APPS that work with AD and everything.
How can i do that in new Azure Portal?
Demonstrated on this screnshot using same account: https://dl.dropboxusercontent.com/u/16550256/azure%20vs%20azure.png
Everything I find on this matter regards the OLD azure management.
New Portal doesn't support Azure AD management yet, not all services are migrated yet, for example Service Bus is still there too. Unfortunately at the time of this writing you have to use both portals, but prefer New Portal if you can. Some new features like resource groups are not available in Classic Portal, and some like AAD not available in the new one.
I had the same problem. If you do not have access to the old Azure platform, you can still register your app here to get access to the Office 365 API and the Graph API. This service has almost the Azure AD functionality.