Thanks @laurent. Yes, there is a link to Open profile directory on the Help menu:
That is how I got the screenshot in C:\Users\john.config\joplin-desktop:
I just don't know what to do next: what I see in C:\Users\john.config\joplin-desktop doesn't match the information in How can I delete a profile (How can i delete a profile).
Thanks for some guidance on this.
John