public async Task<JsonResult> CallOut(string number, string conferenceId) {
            try
            {

                
                var factory = new WebApiClientFactory().CreateClient<ICalloutApiEndpoints>("https://api.sinch.com",
                    new ApplicationSigningFilter(appKey, Convert.FromBase64String(appSecret)), new RestReplyFilter());
                
                number = number.StartsWith("+") ? number.Trim() : "+" + number.Trim();
                var result = await factory.AddParticipant(new CalloutRequest
                {
                    method = "conferenceCallout",
                    conferenceCallout = new ConferenceCallout
                    {
                        cli = "+17864088194",
                        destination = new Destination {endpoint = number, type = "number"},
                        domain = "pstn",
                        conferenceId = conferenceId,
                        greeting ="Welcome to the conference",
                        enableDice = true,
                        enableAce=true,
                    }
                });
                Debug.WriteLine(result.callId);
                return Json(null, JsonRequestBehavior.AllowGet);
            }
            catch (Exception e)
            {
                Debug.WriteLine(e.Message);
            }
            return Json(null, JsonRequestBehavior.AllowGet);
        }