static async Task Main(string[] args)
        {
            var config       = LoadAppSettings();
            var authProvider = new ClientCredentialsAuthProvider(config);

            //authenticate
            await GetAccessToken(authProvider);

            //grab the Graph data
            await GetDirectoryUsers(authProvider);

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }
        private static async Task GetAccessToken(ClientCredentialsAuthProvider authProvider)
        {
            try
            {
                var result = await authProvider.GetAccessTokenAsync();

                Console.ForegroundColor = ConsoleColor.Green;
                Console.WriteLine("Auth token acquired :)");
                // Console.WriteLine(result);
                Console.WriteLine(string.Empty);
            }
            catch (MsalServiceException ex) when(ex.Message.Contains("AADSTS70011"))
            {
                Console.ForegroundColor = ConsoleColor.Red;
                Console.WriteLine(ex.Message);
            }

            Console.ResetColor();
        }