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

fetch('https://api.keystoneos.xyz/v1/platforms/me/webhooks/{endpoint_id}/test', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "success": true,
  "status_code": 123,
  "duration_ms": 123,
  "error": "<string>"
}