I want to add "anchor" tag adjacent to every "list item" that has children.

this is my Walker_Nav_Menu class:

    class Menu_Walker extends Walker_Nav_Menu {

    function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {

        $ident = str_repeat( "\t", $depth );
        
        if ( $args->walker->has_children ){

            $classes = 'menu-item-has-children menu-item menu-item-' . $item->ID;

            // actual link
            $output .= "$ident<li class=\"$classes\"><a href=\"$item->url\">$item->title</a></li>\n";

            // added tag after
            $output .= "<a class=\"added\" href=\"#\">txt</a>";

        } else {

            $classes = 'menu-item menu-item-' . $item->ID;

            // actual link
            $output .= "$ident<li class=\"$classes\"><a href=\"$item->url\">$item->title</a></li>\n";
        }
    }
}

This is the structure of the menu in wordpress:

[![enter image description here][1]][1]


But the output is not nested correctly as you can see in image below:

[![enter image description here][2]][2]


  [1]: https://i.sstatic.net/WBaKM.jpg
  [2]: https://i.sstatic.net/efMzO.jpg

Please help me fix this problem