singular.php

<?php
// for Posts and Pages
/**
 * The template for displaying single posts and pages.
 *
 * @copyright  Copyright (c) 2020, Danny Cooper
 * @license    http://opensource.org/licenses/gpl-2.0.php GNU Public License
 */

get_header(); ?>
<div class="content-wrapper">

  <div class="site-content">
    <?php
    while (have_posts()) :

      the_post();
    ?>

      <article <?php post_class(); ?>>

        <?php the_post_thumbnail('my-custom-image-size'); ?>

        <header class="entry-header">
          <?php the_title('<h1 class="entry-title">', '</h1>'); ?>
        </header><!-- .entry-header -->

        <div class="entry-content">
          <?php the_content(); ?>
        </div><!-- .entry-content -->

      </article><!-- #post-## -->

    <?php
      // If comments are open or we have at least one comment, load up the comment template.
      if (comments_open() || get_comments_number()) :
        comments_template();
      endif;

    endwhile;
    ?>
  </div><!-- .site-content -->
</div>
<?php
get_footer();