curl --request POST \
  --url https://idaas.yourflexpay.com/api/v1/transactions/{reference}/reject \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "reason": "<string>"
}
'

{
  "success": true,
  "message": "<string>",
  "errorCode": "<string>",
  "data": {
    "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
    "reference": "TXN-16820000-AB1C2D3E",
    "senderTag": "@alice",
    "senderAppName": "WalletApp",
    "senderAppId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "receiverTag": "@bob",
    "receiverAppName": "PaymentsApp",
    "receiverAppId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "amount": 1500,
    "currency": "NGN",
    "status": "AWAITING_ACCEPTANCE",
    "narration": "School fees payment",
    "expiresAt": "2023-11-07T05:31:56Z",
    "acceptedAt": "2023-11-07T05:31:56Z",
    "rejectedAt": "2023-11-07T05:31:56Z",
    "rejectionReason": "<string>",
    "createdAt": "2023-11-07T05:31:56Z",
    "updatedAt": "2023-11-07T05:31:56Z",
    "webhooks": [
      {
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "transactionId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "transactionReference": "TXN-16820000-AB1C2D3E",
        "applicationId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "applicationName": "<string>",
        "direction": "RECEIVER",
        "targetUrl": "https://app-b.example.com/webhooks/transactions",
        "eventType": "TRANSACTION_INITIATED",
        "status": "PENDING",
        "attempts": 123,
        "lastError": "<string>",
        "lastAttemptAt": "2023-11-07T05:31:56Z",
        "deliveredAt": "2023-11-07T05:31:56Z",
        "createdAt": "2023-11-07T05:31:56Z",
        "updatedAt": "2023-11-07T05:31:56Z"
      }
    ]
  },
  "errors": [
    "<string>"
  ],
  "timestamp": "2023-11-07T05:31:56Z"
}