Go to Settings > Notes > Password. Tap Reset Notes Password. Enter your Apple ID password. Tap Reset Notes Password again.
Reset your notes password if you forgot it If you forgot the password, Apple can't help you regain access to your locked notes. You can create a new password, but this won't give you access to your old notes. A new password will let you password protect any notes that you create going forward with the new password.
To unlock a note, you need to enter the password that it's locked with. If you forgot the password, Apple can't help you regain access to your locked notes. You can create a new password, but this won't give you access to your old notes.
However, you can't recover notes you permanently removed.
Way 4. Recover Permanently Deleted Notes on iPhone via iCloud.com
Open the shared notebook where you lost recent notes. Click History > Notebook Recycle Bin > Notebook Recycle Bin. If your deleted notes are found there, right-click the page tab that you want to restore, and then use the Move or Copy command to put the notes back in their original location.
You can recover deleted Notes on your iPhone through the Notes app or an iCloud backup, if you've accidentally deleted a Note that you need. You can recover "Recently Deleted" Notes from a folder of the same name within the Notes app, which is a pre-installed iPhone app that functions like a very basic word processor.
If you're missing notes on your iPhone, iPad, or iPod touch
Steps for recovering deleted notes on iPhone 11 from iCloud.com
Recover deleted notes After deleting a note, you have seven days to recover it. Click or tap a note to open it. Restore.
Sign into iCloud.com and select Notes app. Choose "Recently Deleted" folder. Click “Recover” in the toolbar to get back notes disappeared from Mac. Or you can drag the notes from “Recently Deleted” folder to another one.
Android. Open the note you want to restore from the Trash, tap the More actions button (three dots), then tap Restore note.