Trying to authenticate - documentation links broken, options unclear

I’m trying to authenticate with Azure to dynamically scale SQL Azure databases.

There’s a FromUser method on AzureCredentialsFactory, but the parameters are not explained and there are no examples (should qualify: that I can find). I’ve guessed that Client ID in this case is some unique string, similar in function to a User-Agent header. All I get when calling Azure.Authenticate(...).WithDefaultSubscription() on the returned object is:

Exception thrown: 'System.Collections.Generic.KeyNotFoundException' in System.Private.CoreLib.dll: 'The given key was not present in the dictionary.'
   at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at Microsoft.Azure.Management.ResourceManager.Fluent.Authentication.AzureCredentials.<ProcessHttpRequestAsync>d__25.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Azure.Management.ResourceManager.Fluent.SubscriptionsOperations.<ListWithHttpMessagesAsync>d__7.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Azure.Management.ResourceManager.Fluent.SubscriptionsOperationsExtensions.<ListAsync>d__2.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at Microsoft.Azure.Management.ResourceManager.Fluent.Core.Extensions.Synchronize[TResult](Func`1 function)
   at Microsoft.Azure.Management.ResourceManager.Fluent.SubscriptionsImpl.List()
   at Microsoft.Azure.Management.Fluent.Azure.Authenticated.WithDefaultSubscription()

Unfortunately, the documentation:

https://github.com/Azure/azure-libraries-for-net/blob/master/AUTH.md

1. Doesn’t explain this method or params
2. Suggests FromServicePrincipal, then links to https://github.com/Azure/azure-libraries-for-net/blob/master/AUTH.md#creating-a-service-principal-in-azure which doesn’t exist

If I don’t want to use the file-based approach (“an experimental feature that may or may not be available in later releases”), please, any tips?

[hovsepm]

@kierenj you can find authentication information on here - https://docs.microsoft.com/en-us/azure/active-directory/develop/active-directory-authentication-scenarios

[kierenj]

Just a quick note that the “service principal registration” link is still linking nowhere.