The assigned UUID must match the Version 4 UUID standard. To help you validate your UUID format, here is the link to an online validator.
The UUID is visible in the following places:
The URL of the product in the PIM,
and the product API.
Update your products with imports
When exporting your products from the PIM, your downloaded files can now contain a new column named “UUID”. Unlike the identifier attribute, you are sure that all your products have a UUID, meaning it is the best way to update your products when re-importing your file in the PIM.