To enable Pinterest Rich Pins for your products follow these simple steps;
Thats it, if your request is authorised you will recieve an email from Pinterest and your products will then show rich pins within a day or so.
*For the full URL to enter into the validator you can use any of your products, just log into your admin area, go to Store > Products and select any of your active products. Now go to the advanced tab and copy the full URL underneath the oEmbed URL section. You don't need to do every single product, just the one, and then Pinterest will do the rest for you.