I am writing an .Net Core application with Angular Frontend.

Now users are authenticated with Azure Active Directory, which is configured over the Azure Portal.
The users are succesfully authenticated, but as a developer, I still do not now, which user has authenticated.

There are lots of exmaples how to retrieve the information about the user, which is done with
<https://graph.microsoft.com/v1.0/me>. But when I call this, I am getting an 401 Unauthorized response. So there must be a way to get a Token or something like that.

I am having an client-ID, tenant-ID as well as an AppServiceAuthSession Cookie. Can anyone provide an code example?