For publishers with Amazon Affiliates API credentials, Amazon products can be displayed in Comparison Sets using Datafeedr.

To add your Amazon Product Advertising API Keys, head to Wordpress Admin > Datafeedr API > Configuration.

Once your Amazon API access has been successfully configured, head to Datafeedr API > Comparison Sets.

In order to add products from Amazon to your Comparison Sets, be sure to turn "Query Amazon" to "on."

Once enabled, Comparison Sets will be able to include products from Amazon where applicable.

For more information, check out written documentation here.