connection string app config file to cs file

string path = Path.Combine(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),this.AssemblyCompany), this.AssemblyProduct);

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test_Path1
{
    class Program
    {
        public static string AssemblyCompany = "Company1";
        public static string AssemblyProduct = "App1";
        static void Main(string[] args)
        {
            string connStr = @"Data Source=.\sqlexpress; initial catalog=TEST; integrated security=true;";
            string myweb = @"http://google.com";

            string allConfig = connStr + Environment.NewLine + myweb;
            MyConfig cfg = new MyConfig();
            cfg.Save(allConfig);

            string[] rows = cfg.Read();

            Console.WriteLine(rows[0]);
            Console.WriteLine(rows[1]);
        }
    }

    class MyConfig
    {
        public string ConfigPath
        {
            get
            {
                return Path.Combine(Path.Combine(
                    Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
                    Program.AssemblyCompany), Program.AssemblyProduct);
            }
        }

        public MyConfig()
        {
            if (!Directory.Exists(this.ConfigPath))
                Directory.CreateDirectory(this.ConfigPath);
        }

        public void Save(string config)
        {
            using (StreamWriter s = new StreamWriter(Path.Combine(this.ConfigPath, "MyConfig.txt")))
            {
                s.Write(config);
            }
        }

        public string[] Read()
        {
            using (StreamReader s = new StreamReader(Path.Combine(this.ConfigPath, "MyConfig.txt")))
            {
                return s.ReadToEnd().Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
            }
        }

    }
}

var connectionString = ConfigurationManager.ConnectionStrings["Name"];

public static SqlConnection GetConnection()
        {
            string ConnectionString = null;

            SqlConnection myConn = null;

            try
            {
                ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["connStr"].ToString();
                myConn = new SqlConnection(ConnectionString);
            }
            catch (Exception e)
            {
                throw e;
            }
             return myConn;
        }

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Web;

<connectionStrings>
    
    <add name="connStr" providerName="System.Data.SqlClient" connectionString="data source=YOUR PC NAME;initial catalog=YOUR DATABASE NAME;user id=USERID OF CONNECTION TO DB;password=PASSWORD OF CONNECTION TO DB;"/>
  </connectionStrings>