Display related posts without plugin

// into any page or template
$orig_post = $post;
global $post;
$categories = get_the_category($post->ID);
if ($categories) {
  $category_ids = array();
  foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;
  $args=array(
    'category__in' => $category_ids,
    'post__not_in' => array($post->ID),
    'posts_per_page'=> 2, // Number of related posts that will be shown.
    'ignore_sticky_posts'=>1
  );

  $my_query = new wp_query( $args );
  if( $my_query->have_posts() ) { ?>
    <h4>Related posts</h4>
    <?php
    while( $my_query->have_posts() ) {
      $my_query->the_post();
      get_template_part( '/partials/article-card' );
    } ?>
    <?php	
  }
}
$post = $orig_post;
wp_reset_postdata();