Добавление товара в заказ и пересчет скидки по купону

add_product_order_and_calculate_discount_coupon.php

<?
\Bitrix\Main\Loader::includeModule('sale');
$order = \Bitrix\Sale\Order::load(36065);
$basket = $order->getBasket();
\Bitrix\Sale\DiscountCouponsManager::init(
	\Bitrix\Sale\DiscountCouponsManager::MODE_ORDER, array('orderId' => $order->getId(), 'userId' =>  $order->getUserId())
);
$basketItem = $basket->createItem('catalog', 456279);
$fields = array(
	'QUANTITY' => 2,
	'PRODUCT_PROVIDER_CLASS' => '\\Bitrix\\Catalog\\Product\\CatalogProvider'
);

$basketItem->setFields($fields);
$refreshStrategy = \Bitrix\Sale\Basket\RefreshFactory::create(\Bitrix\Sale\Basket\RefreshFactory::TYPE_FULL);
$result = $basket->refresh($refreshStrategy);

$r = $order->save();