At the moment OptimizePress does not have any kind of direct integration with Shopify.
The reason being that Shopify is typically an ecommerce platform which runs independantly from WordPress. We often do build integrations with other third party systems (like JVZoo, Clickbank, Infusionsoft and others) but Shopify has it’s own process for taking payments and delivering customers to their products – it’s not so much a gateway or payment processor and is rather a full service solution instead
If we do build any integrations for Shopify in the future we’ll be sure to detail this on our blog and in our here in our helpcenter.