How can I access create-react-app over external network - node.js

Question

I have created a simple create-react-app which opens a websocket connection to an equally simple websocket echo server in python.
Everything works fine on my local network, however I'd also like to try to connect from outside my local network. To accomplish this I've forwarded port 3000 on my router to the computer running the create-react-app application and tested by connecting a separate computer through the hotspot on my smartphone to the ip address of my router at port 3000.
This fails without properly connecting to the python websocket echo server.
I can connect from an external network to the create-react-app (the default logo is displayed and the page is displayed properly) however the issue is when using the react app to connect to the python echo server.
Any ideas on where to go from here?
Here is the relevant code in App.js:
// Address and port of the python websocket server
const URL = 'ws://localhost:8765'
class EchoWebsocket extends Component {
ws = new WebSocket(URL);
componentDidMount() {
// Callback function when connected to websocket server
this.ws.onopen = () => {
// on connecting, do nothing but log it to the console
console.log('Opening new websocket #' + URL);
console.log('connected')
console.log('Websocket readyState = ', this.ws.readyState);
}
console.log('Websocket readyState = ', this.ws.readyState);
// Callback function when connection to websocket server is closed
this.ws.onclose = () => {
console.log('disconnected')
console.log('Websocket readyState = ', this.ws.readyState);
// automatically try to reconnect on connection loss
console.log('Opening new websocket #' + URL);
}
// Callback function to handle websocket error
this.ws.onerror = event => {
console.log("WebSocket Error: " , event);
}
}
render() {
return(
<div></div>
);
}
}
I also reference <EchoWebsocket /> later in App.js
Here is the python websocket echo server:
#!/usr/bin/env python
import asyncio
import websockets
async def echo(websocket, path):
async for message in websocket:
await websocket.send(message)
asyncio.get_event_loop().run_until_complete(
websockets.serve(echo, '', 8765))
asyncio.get_event_loop().run_forever()

Answer 1

Changing the ip address in App.js to the ip address of the router and forwarding port 8765 in the router to the computer running the websocket echo server allows this code to work both on the local network and from an external network.