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

fetch('https://sandbox.api.enfinitos.com/v1/offers/{offerId}/reject', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "ok": true,
  "data": {
    "offer": {
      "id": "<string>",
      "fromOrgId": "<string>",
      "toOrgId": "<string>",
      "rightId": "<string>",
      "scope": "<string>",
      "termsRef": "<string>",
      "expiresAt": "2023-11-07T05:31:56Z",
      "derivedRightId": "<string>",
      "contentHash": "<string>",
      "createdAt": "2023-11-07T05:31:56Z"
    }
  },
  "contractVersion": "<string>"
}