Why can't I can't get into my Windows 11 machine running OpenSSH? I keep getting permission denied errors

Question

I have answered my own question. I installed Windows Subsystem for Linux (WSL2) running under Windows 11, and then OpenSSH on both the host Windows machine and the virtual Ubuntu machine. Everything worked great, except that I got permission denied errors when trying to get to the Windows host using OpenSSH. (I was only using the default user/password authentication method to start). All of the web searching (GitHub, Microsoft Learn, Reddit, etc) basically said I had a user-password mismatch.

Yes I did --- but this is because Microsoft separated the idea of a password from a PIN. I am the owner and administrator of my machines, and I log in with a PIN. But OpenSSH server on Windows requires a Windows password, and that is NOT the PIN. My password is the one I use at microsoft.com to download software!!! And the PIN and password cannot be the same.

I expected that my Windows PIN would be my Windows password. And it's not.