test

<?php
/**
 * Template Name: Custom Field Test
 */

get_header(); ?>

<div id="primary" class="content-area">
    <main id="main" class="site-main" role="main">

        <?php
        // Replace 123 with the ID of the order that has the custom field
        $custom_field_value = get_post_meta( 123, 'custom_field_name', true );
        echo 'Custom Field Value: ' . $custom_field_value;
        ?>

    </main><!-- #main -->
</div><!-- #primary -->

<?php get_footer(); ?>