Hi Mackenly, unfortunately third party web services tend not to provide Swagger documentation for their APIs, so typically you need to author them yourself. I usually have a quick google around to see if anything is already available but typically end up doing it myself. If you are doing that, Stoplight is probably the easiest option, because you can copy and paste from either the API documentation or your actual test calls to it, and then export the Swagger at the end. In that case I'd just focus on the endpoints you plan on using to save time.
I'll check with the team in case someone has a Facebook Swagger already in case that helps get you started.