如何在bitfinex交易所上使用websocket获取一对BTCUSD的最新价格？我用这种方法尝试，但没有带来任何好处
<html>
<div id="btc"></div>
<script>
var ws = new WebSocket("wss://api-pub.bitfinex.com/ws/2");
ws.onopen = function(){
ws.send(JSON.stringify({"event":"subscribe", "channel":"ticker", "pair":"BTCUSD"}))
};
ws.onmessage = function(msg){
var response = JSON.parse(msg.data);
var hb = response[1];
if(hb != "hb"){
document.getElementById("btc").innerHTML = "$" + response[1][1];
}
};
</script>
</html>