Problem with "you need to add a GTIN or MPN"

Hey @Grace_01

My pleasure, I’m glad to hear you have utilized the Ad Preview Tool! Have you ensured your products have met the conditions in order to show the parent products? Including the item_group_id in the product feed would ensure that all variant/child products are grouped under the parent product, and variants should never be displayed on their own:

Let me know how you get on,