public void GetExternalSessionURL()
        {
            var general = new General(auth);

            try
            {
                ExternalSessionOptions externalSessionOptions = new ExternalSessionOptions
                {
                    Email = "*****@*****.**",
                    Chrome = "None",
                    Url = "/subscribers/[email protected]",
                    IntegratorID = "your integratorID",
                    ClientID = "your clientID"
                };

                string sessionUrl = general.ExternalSessionUrl(externalSessionOptions);
                Console.WriteLine(string.Format("Session created and accessible at URL: {0}", sessionUrl));
            }
            catch (CreatesendException ex)
            {
                ErrorResult error = (ErrorResult)ex.Data["ErrorResult"];
                Console.WriteLine(error.Code);
                Console.WriteLine(error.Message);
            }
            catch (Exception ex)
            {
                // Handle some other failure
                Console.WriteLine(ex.ToString());
            }
        }