Shopify fetches image URLs itself during import. If the URL needs a login, has a space, or times out, the product imports without images.
Host images on a public CDN. Authentication and Shopify image import do not mix.
The free Shopify CSV checker names the exact line for each problem. The paid Rescue Kit adds 20 more error cases, a template in Shopify's column order, and the same checker as a script for your pipeline.
See the Rescue Kit →