crash – How can I extract my MacBook Pro Notes files so that the data becomes "normal" again after the file system crash of my computer?

My MacBook Pro from 2011 to 2013 or something like a "crash" – the computer's file system was crumbling – when I made a forced manual shutdown because the Notes application did not answer. When I reactivated it repeatedly, it was in MacOS recovery mode and I sent it to a computer expert who examined it. It has been able to save / restore many documents – documents Pages, audio files, images and videos, etc. – and also says that the data is not gone, it's as if they were scrambled or arranged differently now or something of the sort. However, he does not know how to extract the files from my Notes application, which are my most important documents. He says that there could be several ways to proceed but he's not an expert on the Mac file system or the model / operating system in question. How to extract Notes files and recover my data as legible Notes files?