FB Comments allows Facebook users to comment DJ-Catalog2 products.
To enable DJ-Catalog2 Facebook comments open Components -> DJ-Catalog2 ->Options
Choose General settings tab and go to "Social sharing & commenting"
Comments - Select comments type in advert view
Import Facebook SDK - Required by FB Comments, you can disable it if your website imports API in other way
Let's see the example DJ-Catalog2 product with enabled FB Comments plugin: