If you see the error "A shipping service is not specified" despite having specified shipping services, it is likely no Ship To Locations have been selected. The problem can be resolved by following these steps:
- Log in to your eBay Seller Hub.
- Head to your Shipping/Business Policies Section.
- Scroll down and open the Edit option for the current Business Policy you are using for the product.
- Scroll until you find the Ship To Location section.
- Ensure you select at least 1 region and then hit save.
For further assistance, please reach out to marketplace-connect@shopify.com