var ws = new WebSocket('wss://gateway.discord.gg');

var mystring = JSON.stringify({
 "op": 2,
 "d": {
 "token": "<bot token>",
 "properties": {
 "$os": "linux",
 "$browser": "sometestingbrowser",
 "$device": "sometestingdevice",
 "$referrer": "",
 "$referring_domain": "",
 },
 "compress": true,
 "large_threshold": 250,
 }
});

ws.send(mystring);