const { SiteClient } = require('datocms-client');
async function run() {
  const client = new SiteClient('YOUR-API-TOKEN');
  
  const maintenanceMode = await client.maintenanceMode.activate({
    force: true
  });
  
  console.log(maintenanceMode);
}
run();

> node example.js
{
  "id": "4235",
  "active": false
}