JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log"></div>

JavaScript

var websocket = new WebSocket( "wss://api.bitfinex.com/ws");
                   
                     websocket.onopen = function() {
                        $('#log').append('<p style="color:red">'+"已開啟"+'</p>');

                        var sendObj={event:"subscribe",channel:"ticker",pair:"ETHUSD"};
                        
                         /* websocket.send(JSON.stringify(sendObj)) */;
                         websocket.send('{"event":"subscribe","channel":"ticker","pair":"TRXETH"}');
 
                    };

                    websocket.onmessage = function(str) {
                        console.log( str.data );
                         if(JSON.parse(str.data).length>2){
                            $('#log').prepend('<p>'+JSON.parse(str.data)[1]+'</p>');
                         }
                    };