How to call a protected Azure function app by Azure Active Directory authentication in a Win app

[@walkingdadjokes6099]

why use Microsoft.Identity.Client vs Azure.Identity? (Since the app is on Azure and using Azure AD authentication).
I'm not sure why we have to provide FunctionAppKey since the function app was secured by Azure Ad authentication in the previous video. Isn't the whole point of Authentication with a function app to remove the need for providing and managing the function key?

[@anthonystuartmason]

Thanks, that was helpful.

[@mohamedyounesse]

source code???