... либо выбранный автоматически плагином
<?php
$args = array(
'posts_per_page' => 1,
'orderby' => 'rand',
'post_type' => 'product'
);
$random_products = get_posts( $args );
foreach ( $random_products as $post ) : setup_postdata( $post ); ?>
<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
<?php
endforeach;
wp_reset_postdata();
?>