Trouble running IDEA plugin from command line

Hello!

I need to run MetricsReloaded plugin for IntelliJ IDEA Community edition 2017.3 from the command line, as specified in README in plugin's repository https://github.com/BasLeijdekkers/MetricsReloaded.

I have the plugin installed and it works in IDEA, but running "idea metrics -h" in command line does not run the plugin and instead shows help for IDEA command line tool. Running "idea metrics" makes IDEA try to open the project called "metrics" in working directory.

How can I make IDEA see the plugin in command line? Where can I look for help?