sample.py

    def cli_commands(self, cli_group, pass_octoprint_ctx, *args, **kwargs):
        import click
        import sys
        import requests.exceptions
        from octoprint_client import Client, build_base_url

        def _api_command(command):
            host = cli_group.settings.get(["server", "host"])
            host = host if host != "0.0.0.0" else "127.0.0.1"

            port = cli_group.settings.getInt(["server", "port"])

            baseurl = build_base_url(host=host, port=port, prefix="/api")

            api_key = cli_group.settings.get(["api", "key"])

            client = Client(baseurl, api_key)
            r = client.post_command("plugin/psucontrol", command)
            try:
                r.raise_for_status()
            except requests.exceptions.HTTPError as e:
                click.echo("HTTP Error, got {}".format(e))
                sys.exit(1)   
        
            return r

        @click.command("on")
        def turnPSUOn_command():
            """Turn the PSU On"""
            _api_command('turnPSUOn')

        return [turnPSUOn_command]