How to retrieve deleted note from iCloud

See the article Delete and recover notes on iCloud.com - Apple Support

Recover recently deleted notes

You can recover and edit notes you have deleted in the last 30 days on iCloud.com or on your devices that are signed in with the same Apple ID. However, you cannot recover notes you have permanently removed.

1. In Notes on iCloud.com, select Recently Deleted in the folder list on the left.
2. If you do not see Recently Deleted, you do not have any notes in that folder, and there is nothing to be recovered.
3. Select a note, then click Recover in the Notes toolbar.
4. The note moves to the Notes folder.
5. If you wish to move a recovered note directly to a folder you created, drag the note from the Recently Deleted folder to another folder.