curl --request POST \
  --url https://crypto.westminister.tech/api/v1/auth/fiat-currencies \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "fiat_currency": {
    "iso_code": "<string>",
    "display_name": "<string>",
    "fraction_digits": 9,
    "sort_order": 123,
    "is_active": true
  }
}
'

{
  "fiat_currency": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "iso_code": "<string>",
    "display_name": "<string>",
    "fraction_digits": 123,
    "sort_order": 123,
    "is_active": true,
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z"
  }
}