Google Calendar Setup
It is recommended to create a dedicated Google account for your reservation system. This way you can name the account something descriptive like "My Building Amenities". This name will appear to users as the sender on confirmaton and reminder emails.
Once you have done that and logged in to your account, go to the Google Cloud console, create a Google Cloud project for your app, set it in test mode, and create an OAuth client ID with application type "Desktop App". Then download the credentials file and store it in your .gcal-credentials folder (which is expected to be in your project root by default).
Fun Fact
- Confirmation emails are actually just Google Calendar event invites, and therefore users can easily add them to their own calendar, or even whitelist the account to have them added automatically.
- Reminder emails are just event updates. The app server updates the title of the event from "[Resource] Reservation" to "Reminder: [Resource] Reservation" at the appointed time.