I Need help with Key File for GCal

I am not sure of the working WMPUDEV uses for setting up the Google Calendar integration - I know it's in it Beta but some of the settings have changed and you have NOT updated the instructions.

I have followed it but get to Step 12 where it says to Copy the Key file name.

The parrameters are supposed to be something like:
(121345689-privatekey )

However, there is no such listing:

Under the Service Account for OAuth once Ihave created a new Client ID I have the following available.

Clients ID: ends with .apps.googleusercontent.com
Email address (This is submitted to Service Account Email)
Certificate fingerprints: part of the key ???

I have attempted to use client ID and Certificate fingeprints as well as copying the exact file name of the DL Key that I upload to the server....and save and each time I get an error message "Key file does not exist"

Can you tell me WHERE I OBTAIN THE KEY FILE information from ???