Add add-on to receipt

Hello, I’m trying to add the “add-on” along with the fix, because I don’t see it, I discovered that the code placed in it doesn’t work, however, the data is wrong.

How can I add or complement?

<div class="order-addresses">
  <div class="billing-address">
    <h3><?php esc_attr_e('Billing Address', 'woocommerce-delivery-notes'); ?></h3>
    <address>

      <?php
      if (!$order->get_formatted_billing_address()) {
        esc_attr_e('N/A', 'woocommerce-delivery-notes');
      } else {
        echo wp_kses_post(apply_filters('wcdn_address_billing', $order->get_formatted_billing_address(), $order));
      }
      ?>

      <?php
      $billing_address_id = $order->get_billing_address()->get_id();
      $customer_complemento = get_post_meta($billing_address_id, 'billing_complement', true);

      if (!empty($customer_complemento)) {
        echo '<p><b>Complemento:</b> ' . esc_html($customer_complemento) . '</p>';
      }
      ?>

    </address>
  </div>
</div>