Control access to your calendar and reminders on Mac
Some apps and websites can use your calendars and reminders to provide you with services and features. For example, an app might use your calendar to help you schedule an event or set up a reminder.
You can decide which apps are allowed to use your calendar and reminder information.
On your Mac, choose Apple menu > System Preferences, click Security & Privacy, then click Privacy.
Select the checkbox next to an app to allow it to access information from your calendar and reminders. Deselect the checkbox to turn off access for that app.
If you turn off access for an app, you’re prompted to turn it on again the next time that app tries to use your information.