Get 404 error when launching local site http://localhost/~<my short user name>

I think I followed the steps in the post by etresoft "Setting up a local web server on macOS 10.15 “Catalina”"

I get system OK on the Apache config test

And I get "It works!" when I enter http://localhost into my Safari browser.

I get 404 error File not found when I enter http://localhost/~<short user name>

Safari: Version 13.0.5 (15608.5.11)

OS MacOS Catalina 10.15.3 (19D76) on a 2013 (late) Mac Pro.

I have verified the correctness of my files with vi to the best of my ability.

Help