Support is helpful and walks you through everything. The app is a bit complicated to set up. You cannot use this on a Facebook page that already has a Shop setup connected to Shopify, so you'll have to create a new FB page for this. I'm waiting for my marketplace application to be approved for now.
Dosha Angel's Boutique
i used this app and it works great. with help from the support team. Looking forward to learning more about this app.