{
   "id":"clientID10",
   "event":"subscribe",
   "success":true,
   "ts":1682242071080
}

{
   "topic":"PERP_ETH_USDC@openinterest",
   "ts":1682242080006,
   "data":{
      "symbol":"PERP_ETH_USDC",
      "openInterest":1.2741
   }
}
Push interval: push every 1 second if open interest change and 10 seconds force update even if no change. 
{
    "id": "clientID10",
    "topic": "PERP_ETH_USDC@openinterest",
    "event": "subscribe"
}
Parameters
NameTypeRequiredDescription
idstringYid generate by client
eventstringYsubscribe/unsubscribe
topicstringN{symbol}@openinterest
{
   "id":"clientID10",
   "event":"subscribe",
   "success":true,
   "ts":1682242071080
}

{
   "topic":"PERP_ETH_USDC@openinterest",
   "ts":1682242080006,
   "data":{
      "symbol":"PERP_ETH_USDC",
      "openInterest":1.2741
   }
}