rules2.js

const { google } = require('googleapis');

const authClient = google.auth.fromJSON(require('./serviceAccount.json'))

const rules = google.firebaserules({
	version: "v1",
	auth: authClient
});

return rules.projects.rulesets.list({
	name: 'projects/<my-project>',
}).then(res => console.log(res)).catch(console.log);