Google API follow the Oauth 2.0 mechanism. You can either use the plugin to implement the OAuth 2.0 or you can directly implement via API connector-
Check out the screenshot of how you can implement the Oauth 2.0 using the API Connector-
This is an example of google calendar but it’s quite common across google API.
Get your App Id and App Secret from the https://console.developers.google.com/ after registration of your app.
The scope depends upon what sort of API you are trying to access (in my case I am using google calendar API) - You can just google to find the scope.
Also, put the redirect URL into google App.
Profile Endpoint also you can google.
This way you don’t need to worry about storing the token (since token is valid for 24 hrs so this way you automatically get the latest token)
Happy to answer if you have other questions.