First, navigate to your instance's settings in Dashboard, specifically go to User & Authentication -> Social Login from the left bar. From the list of OAuth vendors, enable Google. In the next window, make sure Use custom credentials is enabled, and copy the value of the Authorized redirect URI field (we'll have to paste this in Google Console in a bit). Leave that window open as we'll need to fill in the Client ID and Client Secret values that we'll retrieve from Google Cloud Platform console.