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

fetch('https://api.k0rdent.ai/v1/regions/{region}/projects/{project}/infrastructure/servers/{id}:validate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "valid": true,
  "errors": [
    "<string>"
  ]
}