Answer

Traditionally only the root user is allowed to bind to a port with a number lower than 1024. There are times when it is convenient to allow non-root users to run services which bind to “privileged ports”. There are different approaches, but one tool for authorizing non-root user access to low ports is authbind. The authbind tool allows Tomcat to bind to port 443 directly as an unprivileged user. This approach isn’t an officially supported Hub configuration, but it has been known to work.

Here is a link for authbind: http://manpages.ubuntu.com/manpages/bionic/man1/authbind.1.html. 

Additional information can be found here: https://www.mwells.org/coding/2016/authbind-port-80-443/.