I’m building a Node app that uses http and socket, and i’m exposing my localhost using Ngrok and letting other user connect to my react app using my IP4 Address.

i always get this error :

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at ‘https://a29a-41-109-30-183.ngrok-free.app/socket.io/?EIO=4&transport=polling&t=O-hTmol’. (Reason: Credential is not supported if the CORS header ‘Access-Control-Allow-Origin’ is ‘*’).

I setup the CORS like this :

app.use(
  cors({
    origin: ["http://localhost:5173", "http://192.168.1.6:5173"],
    credentials: true,
  })
);

const server = http.createServer(app);
const io = new SocketIOServer(server, {
  cors: {
    origin: ["http://localhost:5173", "http://192.168.1.6:5173"],
    credentials: true,
  },
});

and on the client side :

const socket = io(backend_url_socket, {
    withCredentials: true,
    extraHeaders: {
      Authorization: `Bearer ${secureLocalStorage.getItem("authToken")}`,
      "Another-Header": "HeaderValue",
    },
  });
  socket.on("connect", () => {});