While using the classic Azure Mobile services, you used to get a key along with a URL for your Mobile Service app. This key was also used to explore the APIs on your backend site & was used as a password.
With new Azure App services all you need to instntiate the mobile service client is the URL like below
private static readonly MobileServiceClient MobileService = new MobileServiceClient("https://thecityapp.club");
There is no key *a second parameter that was available with Azure Mobile services. What is now used as password to explore the APIs on the web?
Supreet,
With App Services/Mobile Apps, the application key is no longer used/required, that is why it is no longer available on the portal. You can instantiate the client with the above code and start consuming the service APIs without that information.
For authentication, please refer to this documentation: https://azure.microsoft.com/en-us/documentation/articles/app-service-mobile-windows-store-dotnet-get-started-users/
I hope this helps.