Rcon problem web application Rust server

Hello, I am trying to develop a web application that allows me to type commands in the Rcon console via the web Browser.
The problem is that every time I send a command I get “[Rcon] Failed to parse message, incorrect format”.

After hours looking for information, I have not found anything to help me. I would appreciate help.

Here is the code:

> <!DOCTYPE html>
> <html lang="en">
> <head>
> 	<meta charset="UTF-8">
> 	<meta name="viewport" content="width=device-width, initial-scale=1.0">
> 	<title>WebSocket</title>
> </head>
> <body>
> 	<h1>WebSockets Rust Server</h1>
> 	<input type="button" value="Send" onclick="webSocketTest();">
> 
> 	<script>
> 		function webSocketTest() {
> 			const rcon = new WebSocket('ws://localhost:28016/1234');
> 			console.log(rcon);
> 
> 			rcon.onopen = function(e) {
> 				rcon.send('status');
> 			}
> 
> 			rcon.onmessage = function(e) {
> 				// Code
> 			}
> 
> 			rcon.onerror = function(e) {
> 				// Code
> 			}
> 
> 			rcon.onclose = function(e) {
> 				// Code
> 			}
> 		}
> 	</script>
> </body>
> </html>