How to create Related Posts AFTER post?

I am a PRO user. I would like to have related posts appear at the bottom of every post. Could I request more detailed instructions?

update)
Sorry, GB Pro?, I am GP Pro user…

Thank you David,

I obtained the following code through web surfing, but there is a bug that retrieves posts from all categories instead of just the same category. Is it possible to fix this?

<div class="related-posts">
	<h4><span><?php $categories = get_the_category();
echo esc_html( $categories[0]->name ); ?></span> Related Posts/h4>
<?php 
$post_id = get_the_ID();
    $cat_ids = array();
    $categories = get_the_category( $post_id );

    if(!empty($categories) && is_wp_error($categories)):
        foreach ($categories as $category):
            array_push($cat_ids, $category->term_id);
        endforeach;
    endif;

    $current_post_type = get_post_type($post_id);
    $query_args = array( 

        'category__in' => wp_get_post_categories($post->ID),
        'post_type'      => $current_post_type,
        'post__not_in' => array(get_the_ID()),
        'posts_per_page'  => '5',
        'orderby' => 'rand'

     );

    $related_cats_post = new WP_Query( $query_args );

    if($related_cats_post->have_posts()):
         while($related_cats_post->have_posts()): $related_cats_post->the_post(); ?>
            <ul>
                <li>
                    <a href="<?php the_permalink(); ?>">
                        <?php the_title(); ?>
                    </a>
                 
                </li>
            </ul>
        <?php endwhile;

        // Restore original Post Data
        wp_reset_postdata();
     endif; ?>
</div>