curl --request GET \
  --url https://data-tools.prd.arrays.org/api/v1/etf/flow \
  --header 'X-API-Key: <api-key>'

{
  "data": [
    {
      "close": "<string>",
      "date": "<string>",
      "expiration_cycle": "<string>",
      "is_fomc": true,
      "net_flow": "<string>",
      "net_flow_in_shares": 123,
      "symbol": "<string>",
      "volume": 123
    }
  ],
  "error": {
    "code": "RESOURCE_NOT_FOUND",
    "details": [
      {
        "field": "<string>",
        "got": "<string>",
        "reason": "<string>"
      }
    ],
    "docs_url": "<string>",
    "examples": [
      "<string>"
    ],
    "hint": "<string>",
    "message": "The requested resource was not found.",
    "suggestions": [
      "<string>"
    ]
  },
  "pagination": "<unknown>",
  "request_id": "<string>",
  "success": true
}