Hi,
I have trouble in configuration for Google calendar + Offline Plugin.
I follow instructions for Google cloud/ Google Auth Platform, but I don’t understand the OAuth 2.0 Playground configuration.
I think that the problem comes from the part of the configuration.
Thank you in advance for your help and propt reply.
Best Regards
Make sure the redirect URI matches between the Playground and your Cloud project. 
On the demo page, there is an example of using the “Create a Calendar Event with Attendee”