Improve related posts

Question

i need a button that load more related posts but i dont know if this is java or just php.

I'm getting related content by using this code in single.php

<!-- Related posts -->

<?php
$custom_taxterms = wp_get_object_terms($post->ID, 'networks', array('fields' => 'ids'));
$args = array(
    'post_type' => 'post',
    'post_status' => 'publish',
    'posts_per_page' => 6,
    'orderby' => 'date',
    'tax_query' => array(
        array(
            'taxonomy' => 'networks',
            'field' => 'id',
            'terms' => $custom_taxterms
        )
    ),
    'post__not_in' => array ($post->ID),
);
$related_items = new WP_Query($args);
if ($related_items->have_posts()) :
echo '<h3 class="related">Related Videos</h3>';
while ($related_items->have_posts()) : $related_items->the_post();
?>
<div class="td-block-row">
    <div class="td-block-span4">
        <div class="td_module_3 td_module_wrap_related td-animation-stack td-meta-info-hide">
            <div class="td-module-image">
                <div class="td-module-thumb">
                    <a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>">
                    <?php if (has_post_thumbnail()) {
                        the_post_thumbnail('td_324x235', array('alt' => get_the_title()));
                    } else {
                        echo '<img src="'.get_bloginfo('template_directory').'/images/no-thumb/td_324x235.png" alt="'.get_the_title().'" />';
                    }
                    ?>
                    </a>
                </div>
                <?php
                $terms = get_the_terms($post->ID, 'networks');
                if (! empty($terms)) {
                    foreach ($terms as $term) {
                        $url = get_term_link($term->slug, 'networks');
                        print "<a href='$url' class='td-post-networks-related'>{$term->name}</a>";
                    }
                }
                ?>
                <span class="duration"><i class="fa fa-clock-o" aria-hidden="true"></i> <?php $text = get_post_meta( get_the_ID(), '_video_info_duration', true ); echo ( $text ); ?></span>
            </div>
            <div class="item-details">
                <h3 class="related-title">
                    <a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
                </h3>
                <span class="date"><i class="fa fa-calendar" aria-hidden="true"></i> <?php echo human_time_diff( get_the_time('U'), current_time('timestamp') ) . ' ago'; ?></span>
                <span class="views"><i class="fa fa-eye" aria-hidden="true"></i> <?php echo getPostViews(get_the_ID()); ?></span>
            </div>
        </div>
    </div>
</div>
<?php
endwhile;
endif;
wp_reset_postdata();
?>

<!-- End related posts -->

Any idea of what i need to do this?