Insert TextBox value in Database and bind DataGridView in Windows Application using C#

Hi! I have two form in c# windows application. In first form have datagridview and second form textbox for insert data into database. When I insert data from second form I must close first form and another start for show data from database in datagridiew. I want click save button second form then close it and show data in datagridview form without close first form. How I can do it?

https://imgur.com/a/nMRvcFX

USE [counterDB]
GO
/****** Object:  Table [dbo].[tblInfo]    Script Date: 04/25/2018 23:06:00 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[tblInfo](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[LastName] [nchar](20) NULL,
	[Name] [nchar](20) NULL,
	[Address] [nchar](20) NULL
) ON [PRIMARY]
GO

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

namespace WindowsForms
{
    public partial class Form1 : Form
    {
        public string dbPath = @"Data Source=User-PC;Initial Catalog=counterDB;Integrated Security=True";
        public Form1()
        {
            InitializeComponent();            
            dataGridView1.Columns[0].DataPropertyName = "LastName";
            dataGridView1.Columns[0].HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
            dataGridView1.Columns[1].DataPropertyName = "Name";
            dataGridView1.Columns[1].HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
            dataGridView1.Columns[2].DataPropertyName = "Address";
            dataGridView1.Columns[2].HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
            dataGridView1.DataSource = GetData();
        
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Form2 frm = new Form2();
            frm.ShowDialog();
        }

        public DataTable GetData()
        {
            DataTable dt = new DataTable();
            SqlConnection con = new SqlConnection(dbPath);
            SqlCommand cmd = con.CreateCommand();
            cmd.CommandText = "select lastname, name, address from tblInfo";
            con.Open();
            try
            {
                dt.Load(cmd.ExecuteReader());
            }
            catch
            { }
            con.Close();
            return dt;
        }
    }
}

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

namespace WindowsForms
{
    public partial class Form2 : Form
    {
        public string dbPath = @"Data Source=User-PC;Initial Catalog=counterDB;Integrated Security=True";
        public Form2()
        {
            InitializeComponent();
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            InsertData(textBox1.Text, textBox2.Text, textBox3.Text);
            this.Close();
        }

        public void InsertData(string LName, string Name, string Address)
        {
            SqlConnection con = new SqlConnection(dbPath);
            SqlCommand cmd = con.CreateCommand();
            cmd.CommandText = "insert into tblinfo(lastname, name, address)values('" + LName + "','" + Name + "','" + Address + "')";
            con.Open();
            try
            {
                cmd.ExecuteReader();
            }
            catch
            { }
            con.Close();
        }
    }
}