“Hello, I logon to fpl via Facebook, I can’t see a way to log onto my account via Facebook here does this mean I can’t link my account?”

To add an account to FFM you need to update your profile on the FPL website - add a password. You can do that at this URL: https://users.premierleague.com/a/profile/update/personal.

Once you’ve done that you can add the username / password to the app as normal.