curl --request GET \
  --url https://api.roxom.com/v1/market/open-interest \
  --header 'X-API-Key: <api-key>' \
  --header 'X-API-Signature: <api-key>'

{
  "data": {
    "openInterest": 1,
    "timestamp": 123
  },
  "error": true
}