2. Secondly, the QR code has expired or failed. The information on the QR code has been deleted or updated. You can try to contact the seller or manufacturer of the necklace for more information.
3. Finally, the gold necklace is a personal tailor-made or customized product. The QR code is only used for internal management or identity confirmation and has no other practical functions. You can communicate directly with the seller or manufacturer to learn more about necklaces.