curl --request POST \
  --url https://getmipay.com/api/v1/virtual-cards/cards/{cardId}/operation \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "action": "topup",
  "amount": 50,
  "currency": "USD"
}
'

{
  "success": true,
  "data": {
    "operation": "topup",
    "card_id": "CARD_123456",
    "new_balance": 20,
    "currency": "USD",
    "status": "success",
    "transactions": [
      {
        "id": "TXN_123",
        "amount": 10,
        "currency": "USD",
        "type": "topup",
        "status": "completed",
        "created_at": "2023-11-07T05:31:56Z"
      }
    ]
  }
}