Capacitor CLI Commands Not Recognized

The command: ionic capacitor build android
does not seem to be recognized by the CLI, instead it prints Usage instructions as if the build command was not recognized. The other ionic capacitor commands seem to work (add, copy, open, etc). Is the documentation out of date, or am I misinterpreting something in the docs? Here’s the ionic info:

Ionic CLI : 5.4.2
Ionic Framework : @ionic/angular 5.1.1

Capacitor CLI : 2.4.0
@capacitor/core : 2.4.0

That command should work. Try updating the Ionic CLI to version 6.x:

# If using the old Ionic CLI
$ npm uninstall -g ionic

# Update to the latest 
$ npm install -g @ionic/cli