some suggestions:

[toddlekan]

Thanks for the awesome library, this helped me a lot! Here are some changes I made:

1. No permission to push, or I would have created a PR:

CalendarAPI.js:29
scopes: ['https://www.googleapis.com/auth/calendar'],
// delegationEmail:
// https://github.com/extrabacon/google-oauth-jwt
// "if access is being granted on behalf of someone else, specifies who is impersonating the service account"
delegationEmail: config.delegationEmail

2. A little easier way to to configure:

   this.config = {
   keyFile: ./credentials/${process.env.GOOGLE_CALENDAR_KEY_FILE_PEM},
   serviceAcctId: 'xxx@xxx.iam.gserviceaccount.com',
   timezone: 'UTC+08:00',
   delegationEmail: 'xxx@xxx.com'
   };

const cal = new CalendarAPI(this.config);

3. To make sure attendees get email notifications:

cal.Events.insert(calendarId, event, {"sendUpdates": "all"})