After benchmarking 14 different legacy versions (ranging from v180 to v250), the clear winner is (Beta).
If you must use the full version, you will need to "sideload" a version from 2020 or earlier that still supports API 16 (Android 4.1+). Download Facebook For Android 4.1.2 BEST
Meta ended support for Android 4.x several years ago. Even if you find an old APK (e.g., version 318 or earlier), it will likely: version 318 or earlier)