If the goods are not sold out after the flash sale in the live broadcast room ends, the merchant can consider restocking. The specific operation methods are as follows:

1. Contact the live broadcast platform: The merchant can contact the customer service of the live broadcast platform to ask whether it is possible to restock. If the platform allows, the merchant needs to provide relevant supporting materials, such as proof of product inventory, application for restocking, etc.

2. Contact the merchant's customer service: The merchant can contact its own customer service to ask whether it is possible to restock. If it is possible, the merchant needs to provide relevant supporting materials, such as proof of product inventory, application for restocking, etc.

3. Contact consumers: If the merchant cannot restock, it can try to contact consumers who have already purchased the goods and ask whether they are willing to return the goods, and return the refund to the consumer. If the consumer agrees to return the goods, the merchant can restock and put the goods back on the shelves for sale.

It should be noted that restocking may affect the price and inventory of the goods, and the merchant needs to make adjustments based on the actual situation. In addition, merchants also need to pay attention to the time and method of restocking to avoid inconvenience to consumers.