static void Main(string[] args) { // Find your Account Sid and Auth Token at twilio.com/user/account string AccountSid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"; string AuthToken = "your_auth_token"; var twilio = new TwilioRestClient(AccountSid, AuthToken); var options = new ApplicationOptions(); options.VoiceUrl = "http://demo.twilio.com/docs/voice.xml"; options.SmsUrl = "http://demo.twilio.com/docs/sms.xml"; twilio.UpdateApplication("AP2a0747eba6abf96b7e3c3ff0b4530f6e", null, options); }