How I Write Data From Databse To File

protected void ExportExcel(object sender, EventArgs e)
{

    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT * FROM Customers"))
        {
            using (SqlDataAdapter sda = new SqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataTable dt = new DataTable())
                {
                    sda.Fill(dt);
                    using (XLWorkbook wb = new XLWorkbook())
                    {
                        wb.Worksheets.Add(dt, "Customers");
                        Response.Clear();
                        Response.Buffer = true;
                        Response.Charset = "";
                        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                        Response.AddHeader("content-disposition", "attachment;filename=SqlExport.xlsx");
                        using (MemoryStream MyMemoryStream = new MemoryStream())
                        {
                            wb.SaveAs(MyMemoryStream);
                            MyMemoryStream.WriteTo(Response.OutputStream);
                            Response.Flush();
                            Response.End();
                        }
                    }
                }
            }
        }
    }
}