The 'success' message was returned when calling the changing the status to product in preparation API, but in WING system continues to expose 'payment completed' status. Due to a surge in incoming orders, some system delays may occur. Usually, even if there is a delay, it is processed within 30 minutes. If the status does not change after more than an hour of preparation, please make an online inquiry. Related articles Changing the status to Product in Preparation Is it possible to change the shipping address when the order is in the product in preparation status? Is there a limit to the speed of requests for product registration and modification API usage? Answer to Inquiries via Coupang Contact Center The error 'duplicated item name exists' occurs when modifying the product with API.