const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({osImage: '<string>', configuration: {}})
};

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

{
  "jobId": "<string>",
  "status": "queued"
}