Create and delete reminders on iCloud.com
Each reminder you create is put in a reminder list.
Create a reminder
In Reminders on iCloud.com, select a list for the new reminder, then do one of the following:
If you are using upgraded reminders, click
to add a reminder to the bottom of the list.You can also add a reminder below an existing reminder. Select the title of the reminder, then press Return or Enter.
If you are not using upgraded reminders, click New Item.
Tip: To create a reminder from the iCloud.com homepage, click
in the corner of the Reminders tile. To create a new reminder from anywhere on iCloud.com, click 
in the toolbar, then click Reminder.Type the reminder (for example, “dentist appointment”) in the text field that appears, then press Return or Enter.
Add details to a reminder
If you are using upgraded reminders, you can add a note to a reminder. If you are not using upgraded reminders, you can add a note, add an alert and assign a priority to a reminder.
Note: If you are using upgraded reminders, you can also view certain details — like tags, due dates or flags — on iCloud.com. Use the Reminders app on a device with iOS 13, iPadOS 13, macOS 10.15 or later to add details.
In Reminders on iCloud.com, select the reminder you want to add details to, then do any of the following:
Add a note: If you are not using upgraded reminders, click Details, then type a description or other information in the text field. To read a note later, select the reminder, then click the Details button.
If you are using upgraded reminders, type a description or other information in the notes field.
Receive an alert: click Details. Select “On a day”, then set the date and time you want to be reminded. Click the Never Repeat pop-up menu, then choose a reminder interval.
Assign a priority: click Details. Click the Priority pop-up menu, then choose an option. Prioritised items appear with one, two or three exclamation marks in the reminder list.
Delete a reminder
WARNING: When you delete a reminder, it is deleted on every device with Reminders turned on in iCloud settings. If you are using upgraded reminders and delete a reminder with subtasks, the reminder and all its subtasks are deleted.
In Reminders on iCloud.com, select the list where the reminder appears, then select the reminder you want to delete.
Do one of the following:
Press the Delete or Backspace key.
If you are not using upgraded reminders, you can also click Details, then click Delete in the Details window.
Note: If you accidentally delete reminders and you are not using upgraded reminders, you can restore an archived version of your reminders. See Restore your reminders on iCloud.com.