how do I copy all of my notes onto a hard drive

I am a writer and have created 99% of my material in Notes stored in the cloud.

There have been too many occasions when I have been unable to access the cloud so I'd like to make a backup of all those notes on a hard drive but cannot see an obvious way of doing this. Has anyone else done this and, if so, please will you tell me how.

Thank you

Dave (June 2020)