You don't. You have to use the Facebook app (without beta) to take advantage of the integration into the people hub. The Facebook app in WP8.1 is ahead of both the beta version and the stable version in WP8.0 because it has new code for the social integration and share contracts.
The regular Facebook app store listing actually points to two apps of different versions. If you're on 8.0, the listing points to some 5.x version while if you're on 8.1, it points to some 8.x version of Facebook. Facebook Beta is a slight update from the 5.x version. So in terms of how up to date each version is, it goes Facebook for WP8 (oldest), Facebook Beta, Facebook for WP8.1 (newest).
In short, download the regular Facebook app. It's more up to date than the beta.