Cant access my locked notes

By entering the password you selected when locking the note.

Sorry, but there is no “backdoor” to unlock the note.

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.

Additional details are provided in this section of the iOS User Guide:

https://support.apple.com/en-au/guide/iphone/iphf177bb154/ios

How to lock notes on your iPhone, iPad, and iPod touch - Apple Support

The document also talks about forgotten passcodes.