Add Button in DatagridView C#

DataTable dt = new DataTable();

dt.Columns.Add("id");
dt.Columns.Add("name");

 for (int i = 1; i < 21; i++)
 {
    dt.Rows.Add(DateTime.Now.ToString("hhmmssffffff")+"-"+i,
                "Juan"+i+" Tamad"+i);
  }

            DataGridViewButtonColumn btn = new DataGridViewButtonColumn();
            dataGridView1.Columns.Add(btn);
            btn.HeaderText = "Button";
            btn.Text = "Button";
            btn.Name = "btnClick";
            btn.UseColumnTextForButtonValue = true;
            btn.DisplayIndex = 0;

dataGridView1.DataSource = dt;

dataGridView1.Columns[0].Visible = false;

dataGridView1.Columns[0].Visible = true;

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

namespace AddButtonInDataGridView
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        DataTable dt = new DataTable();

        private void Form1_Load(object sender, EventArgs e)
        {
            dt.Columns.Add("id");
            dt.Columns.Add("name");

            for (int i = 1; i < 21; i++)
            {
                dt.Rows.Add(DateTime.Now.ToString("hhmmssffffff")+"-"+i,
                            "Juan"+i+" Tamad"+i);
            }

            DataGridViewButtonColumn btn = new DataGridViewButtonColumn();
            dataGridView1.Columns.Add(btn); // .Columns.Add(btn);
            btn.HeaderText = "Button";
            btn.Text = "Button";
            btn.Name = "btnClick";
            btn.UseColumnTextForButtonValue = true;
            btn.DisplayIndex = 0;

            dataGridView1.DataSource = dt;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            dataGridView1.Columns[0].Visible = true;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            dataGridView1.Columns[0].Visible = false;
        }

    }
}