<?php
namespace TbiBank\FusionPay\Observer;

use Magento\Framework\Event\ObserverInterface;
use Magento\Framework\Event\Observer;

class TransferCustomFieldsToOrderItem implements ObserverInterface
{
    public function execute(Observer $observer)
    {
        $quoteItem = $observer->getEvent()->getItem();
        $orderItem = $observer->getEvent()->getOrderItem();

        // Transfer custom fields from quote item to order item
        if ($quoteItem->getData('scheme_id')) {
            $orderItem->setData('scheme_id', $quoteItem->getData('scheme_id'));
        }
        if ($quoteItem->getData('downpayment')) {
            $orderItem->setData('downpayment', $quoteItem->getData('downpayment'));
        }
    }
}