Installing the Twilio NuGet package

NuGet\Install-Package Twilio.AspNet.Mvc -Version 6.0.0

After installing the Twilio package, we are going to modify the web config with the account SID and the auth token found from the Twilio dashboard

  <appSettings>
    <add key="config:AccountSid" value="AC3936d9aqq2323fedbdddd0ecd6df37199" /> <!--Replace with your AccountSid-->
    <add key="config:AuthToken" value="52b86f79c19bsassasasas704110dddddc26" />  <!--Replace with your AuthToken-->
    <add key="config:TwilioPhoneNum" value="+1845344098435" />  <!--Replace with your TwilioPhoneNum-->
  </appSettings>

The next part of our application is the API controller that will receive our requests. Let’s create the SmsController class within a Controllers folder:

using System;
using System.Configuration;
using System.Web.Mvc;
using Twilio;
using Twilio.Rest.Api.V2010.Account;

namespace TwillioMVC.Controllers
{
    public class SmsController : Controller
    {
        // GET: Sms
        public ActionResult Index()
        {
            return View();
        }
         
        public ActionResult Create()
        {
             string accountSid = Convert.ToString(ConfigurationManager.AppSettings["config:AccountSid"]);
 string authToken = Convert.ToString(ConfigurationManager.AppSettings["config:AuthToken"]);
 string phone = Convert.ToString(ConfigurationManager.AppSettings["config:TwilioPhoneNum"]);

 TwilioClient.Init(accountSid, authToken);

 var call = CallResource.Create(
     url: new Uri("http://demo.twilio.com/docs/voice.xml"),
     to: new Twilio.Types.PhoneNumber("receiver contact"),
     from: new Twilio.Types.PhoneNumber(phone)
 );

        }

    }
}

So, this is how we can integrate Twillio in Asp.net  and send voice call or make voice call using Twillio in Asp.net.