Chattanoogan
Sorry, but there is no recovery method.
Notes are already secured by multiple layers of cryptologically secure - but recoverable - means.
Adding an additional password is an optional, “extra security layer” for which the user takes full responsibility for recovery.
See following iOS User Guide excerpt:
Important: If you forget your notes password, and you can’t use Face ID or Touch ID to unlock your notes, you won’t be able to view your locked notes, and Apple can’t help you regain access to those locked notes.
Ref: Lock your notes on iPhone – Apple Support (AU)