Open Safari and go to you can’t open the page, learn what to do. Then, check that you turned on Contacts, Calendars, and Reminders* in your iCloud settings.
Make sure that the date and time settings on your iPhone, iPad, iPod touch, Mac, or PC are correct.If a reminder isn't showing up on some devices, make sure that you're running the latest iOS, iPadOS, or macOS on each device. Upgraded reminders and shared reminders in iOS 13 or later or macOS Catalina or later aren't compatible with earlier versions of iOS or macOS.
Check if you still need help after each of the steps below.
