Why items don't have GTIN/UPC number included?

Please note that from the many products that we offer, no one can guarantee that all are eligible to be placed in the google/FB shop.

In most cases, those items don't have a GTIN/UPC number included, or instead, have a tag "Does Not Apply".

Items that are rejected, you can simply disable from feed and re-fetch, or even remove from the store if your only traffic is just from ads.

Go to the specific product on your WSR site and then to Dashboard - Catalog - Product, click edit on the product in question, and under the FEED tab, uncheck "List on Google shopping". This will remove that specific item from the feed. Now you can repeat this same step for other products as well.

Google Shopping and Facebook are user-friendly platforms, and under their policy, you can easily find which items are allowed or not to be a subject of ads.