Events and/or Reminders are not displayed
NotePlan syncs with your iCloud Events (what you see in the Apple Calendar) and dated Reminders (what you see in the Reminders app).
1. If you don't see either or any in the right sidebar of NotePlan, make sure the permissions are still set under "Security & Privacy" on Mac:
On iOS, you can open NotePlan in the preferences app and see if both are enabled.
2. In the preferences under "Calendar" on Mac, you can request the permissions again.
3. If you still don't see reminders, make sure the reminders have a date defined ("On a Day"). A time is optional.
4. Lastly, try to restart your devices. You can also try to log out and back into your iCloud account.