wp-duckbehaviorjournal/single-letter.php

<?php get_header(); ?>

<!-- Letter Content -->
<section class="container my-5">
    <div class="row">
        <div class="col-lg-10 mx-auto">
            <?php if (have_posts()) : while (have_posts()) : the_post(); ?>
                    <h1 class="display-4"><?php the_title(); ?></h1>
                    <p class="text-muted">
                        <?php
                        $authors = get_post_meta(get_the_ID(), 'article_authors', true);
                        if (!empty($authors)) {
                            echo implode(', ', array_map('esc_html', $authors));
                        } else {
                            the_author();
                        }
                        ?> | <?php the_date(); ?>
                    </p>
                    <?php if (has_post_thumbnail()) : ?>
                        <img src="<?php the_post_thumbnail_url(); ?>" class="img-fluid mb-4" alt="<?php the_title(); ?>">
                    <?php endif; ?>
                    <?php the_content(); ?>
            <?php endwhile;
            endif; ?>
        </div>
    </div>
</section>

<?php get_footer(); ?>