Basically I have talked with the support of Amazon so they said in there policy they doesn't allow to use there thumbnail directly on another site they provide embedded code if we use that then there is no problem.

Embed code will have the same problem. Amazon doesn’t allow images for product blocks but I never heard that someone has problem with product thumbnails on site

As i know Amazon doesn't allow to use there images directly, they provide some embedded code. How to use this embedded code in post thumbnail.