The public API /products/* is missing field UPC.
All fields on the ShipStation Products dashboard UI should be included in the response and allowed to be updated via the API.
Include UPC in the following API endpoints response.
Allow update via this update.
There should also be proper documentation schema available for the API such as Request Body keys and available value types.
A good example would be this API documentation https://docs.sendgrid.com/api-reference/link-branding/create-a-branded-link