Buy with Prime is for US-based merchants with an ecommerce site. See the additional standard requirements for Buy with Prime. Buy with Prime for Salesforce Commerce Cloud works best for merchants 1) with storefronts built on Salesforce’s SFRA, 2) that use the Salesforce order management system (OMS), and 3) that use Amazon Pay or Adyen’s Amazon Pay integration as their payment service provider. Those that use Salesforce’s Site Genesis or Lightning Components can use the cartridge, but it requires customization. For merchants that use a different OMS ot payment providers, integration requires additional customization.