add attributes on achor in wordpress navigation menu

//dropdown toggle
add_filter( 'nav_menu_link_attributes', 'add_class_to_items_link', 10, 3 );

function add_class_to_items_link( $atts, $item, $args ) {
  // check if the item has children items
  $hasChildren = (in_array('menu-item-has-children', $item->classes));
  if ($hasChildren) {
    // add the desired attributes:
    $atts['class'] = 'dropdown-toggle';
    $atts['data-toggle'] = 'dropdown';
    $atts['data-target'] = '#';
  }
  return $atts;
}