Okay, I think I found what was wrong. Evidently the directions are totally incorrect. Here are the correct ones in the latest version on Debian 11:
See left panel
Look for down arrow icon and select it
At bottom of list is “Add Account+”, and select it.
This is just a simply layout problem, but the keyboard shortcut, Ctrl-J, can help here. The movement between windows and settings and other parts are a little bit of a mishmash, but it can be easily fixed with a little tweaking.
Now to find out if it will work with my service provider to handle text messaging.