curl --request POST \
  --url https://api.balansas.com/functions/v1/customer-api/fiat-accounts \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "accountName": "<string>",
  "ibanCountry": "<string>",
  "umbrellaLinkId": "3c90c3cc-0d44-4b50-8888-8dd25736052a"
}
'

{
  "data": {
    "id": "a3f1c2e4-5b6d-7e8f-9a0b-1c2d3e4f5a6b",
    "fr_account_id": "facc_3kZ9xQ2mLpV",
    "account_name": "EUR Operating",
    "currency": "EUR",
    "balance": 1250.75,
    "status": "active",
    "is_master": true,
    "linked_business_id": null,
    "fr_owner_business_id": "busi_8Jh2KdLm5Qx",
    "iban": "GB29NWBK60161331926819",
    "account_number": "31926819",
    "sort_code": "601613",
    "routing_number": "026073150",
    "created_at": "2026-05-28T11:02:09.456Z",
    "updated_at": "2026-05-28T11:02:09.456Z"
  }
}