Adapt to whatever host serves the client

src/index.ts

@@ -18,7 +18,7 @@ import {} from "./net/LoopbackServer";
  */
 
 Select(".GameCanvas").forEachCanvas((c, cx, keys) => {
-    const connection = new Connection<KeyName[], Data>("ws://localhost:9090/base2020.ws");
+    const connection = new Connection<KeyName[], Data>(`ws://${location.host}/base2020.ws`);
     new Main(c, cx, keys, connection.socket);
     c.focus();
 });