This is PWA, should work offline as well.
This is a simple tool, which can be used as Client to test your socket events.
Using this tool, you can connect to SocketIO Backend.
Here we will descripte how to use this tool.
You can Learn more here: https://www.bloggernepal.com/2021/11/socketio-client-online-postman-for-socketio.html
Watch this video https://www.youtube.com/watch?v=VM2XJVZ9SSo