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

fetch('https://api.dolfinai.co/bills/{id}/pay/bank', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "billPaymentId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "authorisationUrl": "<string>",
  "expiresAt": "2023-11-07T05:31:56Z",
  "disclosure": {
    "text": "<string>",
    "termsUrl": "<string>",
    "privacyUrl": "<string>"
  }
}