MC4WP_API_v3::add_ecommerce_store_order_line PHP Метод

    public function add_ecommerce_store_order_line($store_id, $order_id, array $args)
    {
        $resource = sprintf('/ecommerce/stores/%s/orders/%s/lines', $store_id, $order_id);
        return $this->client->post($resource, $args);
    }