Facebook occasionally runs beta programs via Apple’s TestFlight. Some beta versions match stable version numbers like 1257. Check Facebook’s official TestFlight link – but note that as of this writing, the beta is on version 1290+, making 1257 unavailable.
Once the App Store is open, tap on the "Search" tab located at the bottom right corner of the screen. Type "Facebook" into the search bar at the top of the screen and press "Search." download facebook ios 1257 updated
If you have an older device that is jailbroken: the beta is on version 1290+
Locate the blue icon on your iPhone or iPad. despite best efforts
Sometimes, despite best efforts, the exact build may no longer be retrievable. In that case, consider these alternatives: