// Create deposit transaction
const response = await fetch('https://api.wiapay.co/v1/deposit', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'your_api_key',
    'X-Timestamp': Date.now().toString(),
    'X-Signature': calculateHMAC(payload, secret)
  },
  body: JSON.stringify({
    amount: 1000,
    currency: 'TRY',
    customerId: 'customer_123',
    callbackUrl: 'https://yoursite.com/callback'
  })
});

// Response
{
  "success": true,
  "data": {
    "transactionId": "txn_abc123",
    "bankAccount": {
      "bankName": "Ziraat Bankası",
      "iban": "TR12 0001 0012 3456 7890 1234 56",
      "accountHolder": "WiaPay Ltd."
    },
    "expiresAt": "2024-01-15T14:30:00Z"
  }
}