Show images on sub-menu navigation

Display the images on the sub-menu items on the navigation of the site. Add code to the functions.php file:

function add_images_to_special_submenu( $items ) {
    $special_menu_parent_ids = array();
    foreach ( $items as $item ) {
        if ( in_array( 'icon-dropdown-menu', $item->classes, true ) && isset( $item->ID ) ) {
            $special_menu_parent_ids[] = $item->ID;
        }
        if ( in_array( $item->menu_ite