Although we also shared that same tutorial on our own site (it may even still be there) it is the work of someone else and you’d really need to approach them for assistance.
My understanding though is that Tim (the author) doesn’t support that method either now, especially as Community Events has been released.
I have seen some other posts where people really do want to integrate GF instead of using Community Events though, so it may be you can find useful tips around the forum 🙂 sadly, however, we can’t really offer support on an official level for this one.