A simple example using websockets that sends data and receives a response:
let url = "wss://echo.websocket.org"
let ws = new WebSocket(url);
ws.onmessage = function (event) {
console.log("Received message:" + event.data);
}
ws.onopen = function (event) {
console.log("Sent data over websocket");
ws.send("Test");
}