iCloud

Search notes on iCloud.com
You can search the text of all your notes to find a specific note. All folders except the Recently Deleted folder are searched.
In Notes on iCloud.com, tap the search field at the top of the notes list.
If you don’t see the notes list, see Show the notes or folder list in Notes on iCloud.com.
Type the text you want to search for.
To return to the complete notes list and clear the search, tap the Delete button
in the search field.
Locked notes don’t appear in the search results. To search locked notes, select one, then enter your Notes password to open them all.