??@jamesjosephfinn thanks for the ping! As far as I can see, the Buyable Pin API is still a closed API, which is why only Shopify and Bigcommerce can use it — it requires a platform-level integration as a result. (Without an open API, there’s nothing for a plugin developer to build against.)
You could try adding product pin markup to your site and applying to Pinterest for buyable pins, though the “How can I apply to sell on Pinterest?” section here indicates you likely won’t be accepted until Pinterest opens this to more platforms.