How to send SMS through Website

Send mobile SMS using website :- I am using ASP.Net C#.It helps a lot for those who develops a web application like E-commerce, etc.

SOURCE CODE

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
public partial class Phone : System.Web.UI.Page
{
	string CS = ConfigurationManager.ConnectionStrings["MyDatabaseConnectionString"].ConnectionString;
	DataTable dt = new DataTable();
	static int sentOtp = 0;
	protected void Page_Load(object sender, EventArgs e)
	{
	
	}

	protected void btnSend_Click(object sender, EventArgs e)
	{
		using (SqlConnection con = new SqlConnection(CS))
		{
			Random rand = new Random();
			string apikey = "your api key";
			long numbers = Convert.ToInt64(txtPhone.Text);
			sentOtp = rand.Next(1000, 9999);
			string senders = "TXTLCL";
			SqlCommand cmd = new SqlCommand("select * from AdminAccess where phoneNumber ='" + numbers + "'", con);
			con.Open();
			SqlDataAdapter sda = new SqlDataAdapter(cmd);
			sda.Fill(dt);
			if (dt.Rows.Count != 0)
			{
				String url = "https://api.textlocal.in/send/?apikey=" + apikey + "&numbers=" + numbers + "&message=" + sentOtp + "&sender=" + senders;

				StreamWriter mywriter = null;
				HttpWebRequest objrequest = (HttpWebRequest)WebRequest.Create(url);

				objrequest.Method = "POST";
				objrequest.ContentLength = Encoding.UTF8.GetByteCount(url);
				objrequest.ContentType = "application/x-www-form-urlencoded";

				try
				{
					mywriter = new StreamWriter(objrequest.GetRequestStream());
					mywriter.Write(url);

					lblmessage.Text = "OTP Sent Successfully";
					lblmessage.ForeColor = System.Drawing.Color.Green;

					txtOtp.Visible = true;
					btnVerify.Visible = true;
				}

				catch (Exception)
				{
					lblmessage.Text = "OTP could not sent";
					lblmessage.ForeColor = System.Drawing.Color.Red;
				}

				finally
				{
					mywriter.Close();
				}
			}
			else
			{
				lblmessage.Text = "This Phone Number is not present in our database";
				lblmessage.ForeColor = System.Drawing.Color.Red;
			}
		}
	}

	protected void btnVerify_Click(object sender, EventArgs e)
	{
		if (sentOtp == Convert.ToInt32(txtOtp.Text))
		{
			Session["Result"] = "Successful";
			Response.Redirect("~/Admin.aspx");
		}
		else
		{
			lblmessage.Text = "OTP does not matches";
			lblmessage.ForeColor = System.Drawing.Color.Red;
		}
		Session["Result"] = "Successful";
		Response.Redirect("~/Admin.aspx");
	}
}

SOURCE VIDEO