curl --request GET \
  --url https://api.gofermata.com/v1/accounts/{account_id}/balance/{denomination} \
  --header 'Authorization: Basic <encoded-value>'

{
  "data": {
    "account_id": "<string>",
    "denomination": "<string>",
    "amount": 123,
    "last_periodic_refill": null,
    "next_periodic_refill": null,
    "managed_by_plan_id": null,
    "plan_variable_amount": null,
    "created_at": "<string>",
    "updated_at": "<string>"
  }
}