Cancel payment example

curl -X POST "http://127.0.0.1:8887/cancel" \
  -H "Content-Type: application/json" \
  -d '{
    "trans":"123456",
    "pay_id":"ORDER-1001",
    "rrn":"123456789012",
    "amount":12500,
    "currency":"UAH",
    "pay_system":"iPay"
  }'