Fill gride view with DataTable

DataTable dt = new DataTable() ;
           
            string constring = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=POS;Data Source=.";
           
            SqlConnection con = new SqlConnection(constring);

            con.Open();

            SqlCommand scm = new SqlCommand();
            scm.Connection = con;
         
           scm .CommandText= "select Max(id) from Add_item";
       
           SqlDataAdapter dA = new SqlDataAdapter(scm  );
           
     
          dataGridView1.DataSource = dt;