I think you need to use iPhone Data Recovery. It can scan your iPhone 7 and iPhone 7 Plus deeply to find the deleted notes. You can preview the notes before recovering. Learn how to recover deleted notes from iPhone
7. Besides notes, you can also recover deleted messages, photos, videos, contacts, call history, reminders, calendars, voice memos, voicemail, safari bookmarks, Whatsapp messages and other deleted data from your iPhone 7.