Fortnox - Custom price and discount

functions.php

<?php
/**
 * @snippet       WooCommerce - Custom Price functions
 * @author        Redlight Media AB / Christopher Hedqvist
 * @compatible    WooCommerce 6.0.0
 */
function redlight_fortnox_order_item_special_price( $orderItem, $item, $product_id, $order ) {
  $product = wc_get_product($product_id);
  $full_price_products = array('MIL-SATT-40KM','BOM-KOR'); // Out products that should be full price
  if( !in_array( $product->get_sku(), $full_price_products ) ){
      $orderItem['Price'] = $product->get_regular_price(); // Get the regular price of the product
      $orderItem['DiscountType'] = 'PERCENT'; // PERCENT or AMOUNT
      $orderItem['Discount'] = '48.5'; // Our Percentage
  }

  return $orderItem;
}
add_filter('obj_fortnox_order_item_row_data', 'redlight_fortnox_order_item_special_price', 10, 4 );