MW WP FORM サンクスページ

function my_mwform_after_send( $Data ) {
    if ( $Data->get_form_key() === 'mw-wp-form-xxx' ) {
      $id = $Data->get( 'id' ); $url = get_permalink($id);
      wp_redirect($url.'?q=thanks');
      exit;
    }
  }
  add_action( 'mwform_after_send_mw-wp-form-xxx', 'my_mwform_after_send' );