The problem I am having is that "HACS" does not show up anywhere beyond the installer after it successfully executes. So searching for Hubitat from there gets me nowhere with no clear way to add it to the sidebar.
If those steps don't work, you should seek additional help in the Home Assistant Community; they are a better resource to resolve issues related to Home Assistant.
HACS installation authorization was the issue. Out of the dozens of people saying 'install it' and 'follow the instructions in the log', none mentioned that step.