Remove Postmeta from OrderItem

functions.php

<?php
/**
* @snippet WooCommerce - Fortnox plugin by Redlight Media - Remove and Post_meta rows in Fortnox via functions.php
* @author Redlight Media AB / Christopher Hedqvist
* @compatible WooCommerce 3.2.5
*/
function redlight_fortnox_remove_postmeta($orderData) {

    foreach($orderData['Order']['OrderRows'] as $i => $item) {
        if(isset($item['AccountNumber']) && $item['AccountNumber'] == 'API_BLANK')
           unset($orderData['Order']['OrderRows'][$i]);
    }
    sort($orderData['Order']['OrderRows']);

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