چاپ اطلاعات وب سایت در لیبل سی شارپ

سلام من میخوام از سایت سهام یاب مثلا قیمت اخرین معامله رو بگیرم و در لیبل چاپ بشه با زدن دکمه get کدی که من نوشتم اینه میشه بگین چیکار کنم Not found! نشه لطفا

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp15
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            textBox1.Text = "وغدیر"; 
            button1.Text = "Get";
        }

        private void button1_Click(object sender, EventArgs e)
        {

            button1.Text = "Wait...";
            button1.Enabled = false; 
            Application.DoEvents();
            var url = "https://www.sahamyab.com/hashtag/" + textBox1.Text;
            var page = GetPage(url);
            var classId = "ml-1 align-self-center";
            var regex = new Regex("<div _ngcontent-ygd-c30 class=\"" + classId + "\">\\s*(?<price>[^\\<\\s]*)\\s*</div>", RegexOptions.IgnoreCase);
            var match = regex.Match(page);
            label1.Text = (match.Success) ? match.Groups["price"].Value : "Not found!";
            button1.Text = "Get";
            button1.Enabled = true;
        }
        private static string GetPage(string url)
        {
            try
            {
                var request = (HttpWebRequest)WebRequest.Create(url);
                request.CookieContainer = new CookieContainer();
                request.Proxy = WebRequest.DefaultWebProxy;
                request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36";
                request.ProtocolVersion = HttpVersion.Version10;
                request.Accept = "*/*";
                request.ContentType = "text/html";
                request.ContentLength = 0;
                using (var response = (HttpWebResponse)request.GetResponse())
                {
                    var stream = response.GetResponseStream();
                    if (stream == null)
                    {
                        return string.Empty;
                    }
                    using (var reader = new StreamReader(stream))
                    {
                        return reader.ReadToEnd();
                    }
                }
            }
            catch
            {
                return "";
            }
        }
    }
}

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