singular.php

<?php
/**
 * 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="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 -->
<?php
get_sidebar();
get_footer();