Calendar
Why does my calendar display have a red 1 and how do I get rid of it
Question marked as
That đź”´ means you have an invite waiting, or have a change to an event in a shared calendar to review.
Look for the đź“Ą
On an iPhone or iPad, the icon looks like what is circled (image from iPad):
On a Mac, you can also use Calendar app > View > Show Notification