CalEvents Manager requires the following OAuth Scopes:
6 Scopes Requested
Run as a Calendar add-on
https://www.googleapis.com/auth/calendar.addons.execute
See, edit, share, and permanently delete all the calendars you can access using Google Calendar. (This is needed to perform the bulk actions on your calendar events)
https://www.googleapis.com/auth/calendar
View your country, language, and timezone
https://www.googleapis.com/auth/script.locale
See your primary Google Account email address
https://www.googleapis.com/auth/userinfo.email
See your personal info, including any personal info you've made publicly available
https://www.googleapis.com/auth/userinfo.profile
See, edit, create, and delete all your Google Sheets spreadsheets. (This is needed to access data on a specific Google Sheet related to your subscription status not created by the add on.)
https://www.googleapis.com/auth/spreadsheets