Fortnox - Order meta

functions.php

<?php
 /**
 * @snippet       WooCommerce - Fortnox plugin by Redlight Media - Add Ordermeta to field in Fortnox
 * @compatible    WooCommerce 4.1.1
 */
function redlight_fortnox_doorcode( $orderData, $order_id) {
    $order = new WC_Order($order_id);
    $doorcode = $order->get_meta('_doorcode', true);
    if($doorcode){
          $orderData['Order']['Remarks'] .= "\r\n"."Portkod: ".$doorcode;
    }

    return $orderData;
}
add_filter('obj_fortnox_order_data', 'redlight_fortnox_doorcode', 10, 2 );