This gist describes two processes allowing us to access the Google API and to register some webhooks. At the end of both processes we will obtain all variable needed to start using their API and we will have whitelisted all necessary URL to get started. We will be using the Google Calendar API and the Google Plus API to access the email address of the user.
This gist has been created as an Appendix to this article (part 1) and this article (part 3).
Note that, I will be using a randomly generated ngrok domain during this presentation. Simply replace b3093b51.ngrok.io
with your domain name