How do I download multiple file with downloadfileasync C#?

<pre>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.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
using System.Threading;
namespace Ping_Service
{
    public partial class Form1 : Form
    {

        private readonly string Version = "1.1";
        public Form1()
        {
            InitializeComponent();
        }
        WebClient client;
        public string getVersion()
        {
            return Version;
        }
        //Method to Update 
        private void checkForUpdate()
        {
            string URL = "https://tweak-team.ir/";
            string AppName = "PingService.exe";
            string ServerVersion;
            string serverVersionName = "pingservice.txt";
            // i will make take a old app to check if its work :) 

            WebRequest req = WebRequest.Create(URL + serverVersionName);
            WebResponse res = req.GetResponse();
            Stream str = res.GetResponseStream();
            StreamReader tr = new StreamReader(str);
            ServerVersion = tr.ReadLine();


            if (getVersion() != ServerVersion)
            {
                //Update
                WebClient client = new WebClient();
                byte[] appdata = client.DownloadData(URL + AppName);


                MessageBox.Show("Update is Available!", "PingService", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                if (saveFileDialog1.ShowDialog() == DialogResult.OK)
                {
                    
                    using (FileStream fs = File.Create(saveFileDialog1.FileName))
                    {
                        fs.Write(appdata, 0, appdata.Length);
                    }
                }
            }
            else
            {
                MessageBox.Show("No Update is Available!", "PingService", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            checkForUpdate();

        }

        private void bunifuThinButton21_Click(object sender, EventArgs e)
        {
            string[] filePaths = Directory.GetFiles(@"C:\test");
            foreach (string filePath in filePaths)
                File.Delete(filePath);



            Thread thread = new Thread(() => {
                WebClient client = new WebClient();
                client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
                client.DownloadFileCompleted += new AsyncCompletedEventHandler(client_DownloadFileCompleted);
                client.DownloadFileAsync(new Uri("https://pingservice.ir/icon/Server/pingservice-Germany.ovpn"), @"C:\test\pingservice-Germany.ovpn");
                client.DownloadFileAsync(new Uri("https://pingservice.ir/icon/Server/pingservice-Netherland.ovpn"), @"C:\test\pingservice-Netherland.ovpn");
                client.DownloadFileAsync(new Uri("https://pingservice.ir/icon/Server/Ps-Germany-New.ovpn"), @"C:\test\C:\test\Ps-Germany-New.ovpn");

            });
            thread.Start();

        }

        void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            this.BeginInvoke((MethodInvoker)delegate {
                double bytesIn = double.Parse(e.BytesReceived.ToString());
                double totalBytes = double.Parse(e.TotalBytesToReceive.ToString());
                double percentage = bytesIn / totalBytes * 100;
                progressBar1.Value = int.Parse(Math.Truncate(percentage).ToString());
            });
        }
        void client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
        {
            this.BeginInvoke((MethodInvoker)delegate {
                MessageBox.Show("Download Compelte", "PingService");
            });
        }
    }
}