Not working with pm2 ecosystem files

[dibyajyotiron]

Unable to find any documentation which mentions how to use it ecosystem files of pm2.
How do I use this with ecosystem files?

        name: appName,
        script: "./app.js",
        args: "one two",
        instances: 1,
        watch: true,
        ignore_watch: ["node_modules", "logs"],
        env: {
            NODE_ENV,
        },
        log_date_format: "ddd, DD-MMM-YYYY, hh:mm:ss A UTCZ",
        output: logLocation.output,
        error: logLocation.error,