Add an extra post item at the end of a Listing Builder query

<!--To be used in a Listing Builder listing in Dev mode-->
<?php if ( have_posts() ) : ?>
<?php while ( have_posts() ): the_post(); ?>
    <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
<?php endwhile; ?>

<!--Adds an extra post item (for example an ad) at the end of the query-->
<?php if ( $wp_query->max_num_pages == FWP()->facet->ajax_params['paged'] ) : ?>
<div>This is my extra post item<div>
<?php endif; ?>

<?php else : ?>
    <p><?php _e( 'Sorry, no posts matched your criteria.' ); ?></p>
<?php endif; ?>