How to fix Facebook on iOS 6
If it doesn't work for you for some reason
If you are having issues with logging in into your Facebook account on your device running iOS 6, this tutorial might just help you.
But if it doesn't then people will try to help you in the discord server - discord.gg/bag-xml
While this might or might not work for other iOS versions (such as 5.0) I have not tested it.
First of all, get the Facebook .ipa
I recommend you getting it from here,
I recommend downloading the version v11 since it is the latest one for iOS 6 and it works really nicely, (at least on my iPhone 4s)
Now before you do anything, enable 2FA on your Facebook account
It might seem out of the ordinary to enable 2FA on your Facebook account when you wanna try logging in on iOS 6, but trust me.
To enable 2FA, go to the Meta Account Centre, then "Password and security" and "Two-Factor Authentication" I recommend using a authenticator app such as Google Auth or Authy, do the steps that you are given in the app and continue with the next step.
Login to the account on iOS 6 now
Enter your details on your legacy iDevice and (uh-oh) a pop-up should appear along the lines of "Confirm Identity"
Click Open in Safari and you will be taken to a Facebook page with a text-box asking you to put a 2FA code*, to be fair you can completly ignore it and look at the notifications on your main phone, if you got a Facebook notification with a Warning sign, then click "Yes" If you've got the option. The browser should refresh on your older phone and successfully login into your account.
*The browser might crash so keep trying until it doesn't, and if if you can't get it to work still then keep scrolling down when Safari opens (spam scroll to the down)