After Version >= 2.0 you just need the App ID and not Secret.
After Version >= 2.0 do the following steps:
After Version >= 2.0 it's also working with url parsing 'lemonbraingmbh' from 'https://www.facebook.com/lemonbraingmbh/'
Before Version 2.0 use this:
If your Facebook URL hasn't a number at the end, use this tool. Else where use the number at the end of your URL