const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({ttl: 3600})
};

fetch('https://api.example.com/v1/regions/{region}/compute/clusters/{clusterId}/kubeconfigs', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "success": true,
  "data": {
    "kubeconfig": "<string>",
    "expiresAt": "2023-11-07T05:31:56Z"
  }
}