curl --request POST \
  --url https://v2.55-tech.com/cancel-all-orders \
  --header 'x-api-key: <api-key>'

{
  "status": "<string>",
  "cancelledCount": 123,
  "cancelled": [
    {}
  ],
  "notCancelled": {
    "reason": "<string>",
    "orders": [
      {}
    ]
  }
}