I am trying elasticsearch as a standalone search for WordPress. I created a new server on Ubuntu 20.04 LTS with nothing but elasticsearch. I did nothing to the config file, accepting all defaults. It started fine on port 9200. The WordPress plugin needs port 80 (silly thing), so I modifed the yml file to use http.port = 80. There is no web server running on port 80. Netstat proves it. Yet elasticsearch fails to start with bind permission denied. It starts fine on port 9200.
Why? What can be done?