const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.thanks.io/api/v2/sub-accounts/', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "data": [
    {
      "$ref": "#/components/examples/sub-account-example"
    }
  ]
}