Ultimately, I'm going to ask a question about SMTP email, which is the underlying issue, but I'm pretty sure I've done something wrong somewhere in the setup process in general.
I have taken the docker image at osticket/osticket:latest. That gives me this as a basic setup:
osTicket Version v1.15.2 (cb6766e) — Up to date
Web Server Software nginx/1.14.0
MySQL Version 8.0.23
PHP Version 7.2.24-0ubuntu0.18.04.4
There are little question marks which hovering over causes a pop-up window to appear. It's empty.
There's also a System Logs section, but hovering over a log entry shows a login page instead of the log entry.