Facebook stopped working on my iPhone 6

Time for a newer, more modern iPhone if you want to use the Facebook app on iPhone. Your phone is now too old and Facebook no longer supports its app on your device.

iPhone 6s

What is its version iOS? Find the software version on your iPhone, iPad, or iPod - Apple Support

Facebook decided to only support Apple mobile devices with iOS 13.4 or later.

My Facebook stopped working on my iPhone6s what is the problem