I am trying to fetch All product by category. I am unable to fetch product by custom category. I do no what is wrong with this and why this code is not working .Any help Please

<?php     $  terms = get_terms(array('taxonomy' => 'item', 'hide_empty' => false, 'parent' => 0, 'orderby' => 'date', 'order' => 'DESC'));     foreach ($  terms as $  term) {         $  slug = $  term->slug;         $  term_id = $  term->term_id;         $  args = array(             'post_type' => 'product',             'tax_query' => array(                 array(                     'taxonomy' => 'item',                     'terms' => $  slug,                     'field' => 'slug',                 )             ),             'orderby' => 'ID',             'order' => 'DESC',             'posts_per_page' => -1         );         $  loop = new WP_Query( $  args );         //print_r($  loop);         ?>         <div id="<?php echo $  term_id = $  term->term_id; ?>" class="tabcontent">        <?php while ( $  loop->have_posts() ) : $  loop->the_post();             global $  product;             ?>           <?php    echo '<br /><a href="'.get_permalink().'">' . woocommerce_get_product_thumbnail().' '.get_the_title().'</a>';?>                  <?php         endwhile;?>       </div>       <?php }//Close foreach here     ?>        </div>     <?php         wp_reset_query();     ?>