TikTok Shop requires that all products you sell have a GTIN (Global Trade Item Number). However, if you sell products through Printful, they won’t have a GTIN. When pushing a product from Printful to your TikTok store, we automatically set a GTIN exemption so that you don’t have to set it up manually.
Unfortunately, some product types can’t be sold on TikTok Shop without a GTIN, so you won’t be able to add these Printful products to your TikTok store:
You can learn more about the TikTok GTIN policies here.