const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    events: [
      {name: 'widget_open', id: 'e1', props: {page: '/pricing'}},
      {name: 'add_to_cart', id: 'e2', props: {value: 49.9, currency: 'USD'}}
    ]
  })
};

fetch('{protocol}://{host}/api/public/v1/chat/events/batch', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));