title: Display custom meta data in WooCommerce admin order after billing address
body: <p>After having read the answer from 7uc1f3r on <a href="https://stackoverflow.com/questions/64378146/add-a-select-field-with-time-intervals-based-on-opening-closing-and-breaks-time/64941894#64941894">Add a select field with time intervals based on opening, closing and breaks times in WooCommerce checkout</a> I did my best to understand how to add the actual time to the order.</p>
  <p>This was already mentioned in the initial question, but when modifying that code to match the answer code by 7uc1f3r I get a notice on the order page (admin).</p>
  <p><strong>It says:</strong></p>
  <pre><code>Notice: id was called incorrectly. Order properties should not be accessed directly. Backtrace: require('wp-admin/edit-form-advanced.php'), do_meta_boxes, WC_Meta_Box_Order_Data::output, do_action('woocommerce_admin_order_data_after_billing_address'), WP_Hook-&gt;do_action, WP_Hook-&gt;apply_filters, wps_select_checkout_field_display_admin_order_meta, WC_Abstract_Legacy_Order-&gt;__get, wc_doing_it_wrong Please see Debugging in WordPress for more information. (This message was added in version 3.0.) in /wp-includes/functions.php on line 5311
  </code></pre>
  <p>The actual delivery time shows, but with this notice above.</p>
  <p><strong>That said;</strong> I did my best in modifying the code further to check &quot;if&quot; delivery time is not blank and if so, show it. That did not help either - the notice is still there.</p>
  <p><strong>This is what I changed the code into:</strong></p>
  <pre><code>add_action('woocommerce_admin_order_data_after_billing_address', 'wps_select_checkout_field_display_admin_order_meta', 10, 1 );
  function wps_select_checkout_field_display_admin_order_meta( $order ) {
      
      if ( get_post_meta( $order-&gt;get_id(), 'delivery_time' != '' ) ) {
      
          echo '&lt;p&gt;&lt;strong&gt;'.__('Requested Delivery Time').':&lt;/strong&gt; ' . get_post_meta($order-&gt;id, 'delivery_time', true) . '&lt;/p&gt;';
      }
  }
  </code></pre>
  <p>Not sure how to get rid of the notice.</p>