Adiciona opção de archives de posttypes no editor de menu do admin do Wordpress

functions.php

<?php 
function pc_metabox_menu_posttype_archive()
{
    $post_types = get_post_types(['show_in_nav_menus' => true, 'has_archive' => true], 'object');

    if ($post_types):
        $items = [];
        $loop_index = PHP_INT_MIN;

        foreach ($post_types as $post_type) {
            $item = new stdClass();

            $item->object_id = ++$loop_index;
            $item->db_id = 0;
            $item->object = 'post_type_' . $post_type->query_var;
            $item->menu_item_parent = 0;
            $item->type = 'custom';
            $item->title = $post_type->labels->name;
            $item->url = get_post_type_archive_link($post_type->query_var);
            $item->target = '';
            $item->attr_title = '';
            $item->classes = [];
            $item->xfn = '';

            $items[] = $item;
        }

        $walker = new Walker_Nav_Menu_Checklist([]);

        ?>

        <div id="posttype-archive" class="posttypediv">
            <div id="tabs-panel-posttype-archive" class="tabs-panel tabs-panel-active">
                <ul id="posttype-archive-checklist" class="categorychecklist form-no-clear">
                    <?php echo walk_nav_menu_tree(array_map('wp_setup_nav_menu_item', $items), 0, (object)['walker' => $walker]); ?>
                </ul>
            </div>
        </div>

        <p class="button-controls">
            <span class="add-to-menu">
                <input type="submit" class="button-secondary submit-add-to-menu right" value="Adicionar ao menu"
                   name="add-posttype-archive-menu-item" id="submit-posttype-archive"/>
                <span class="spinner"></span>
            </span>
        </p>
    <?php
    endif;
}

function pc_add_metabox_menu_posttype_archive()
{
    add_meta_box('wpclean-metabox-nav-menu-posttype', 'Arquivos Personalizados', 'pc_metabox_menu_posttype_archive', 'nav-menus', 'side', 'default');
}

add_action('admin_head-nav-menus.php', 'pc_add_metabox_menu_posttype_archive');