const options = {method: 'GET'};

fetch('https://api.dolfinai.co/bank-details/countries', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

[
  {
    "countryCode": "<string>",
    "countryName": "<string>",
    "defaultCurrencies": [
      "<string>"
    ]
  }
]