const SiteClient = require('datocms-client').SiteClient;
const client = new SiteClient('YOUR-API-TOKEN');
const workflowId = 'approval_by_editors';
client.workflow.update(workflowId, {
  name: 'Approval by editors required',
  stages: [
    {
      id: 'waiting_for_review',
      name: 'Waiting for review',
      initial: true
    }
  ]
})
.then((workflow) => {
  console.log(workflow);
})
.catch((error) => {
  console.error(error);
});

> node example.js
{
  "id": "approval_by_editors",
  "name": "Approval by editors required",
  "stages": [
    {
      "id": "waiting_for_review",
      "name": "Waiting for review",
      "initial": true
    }
  ]
}