Sockets with Meteor, Connection Timeout in Flutter

Hi Everyone,

Integrated socket io with Meteor using the following code

import io from '';
import { Meteor } from 'meteor/meteor';
import { WebApp } from 'meteor/webapp';

const { httpServer } = WebApp;
        io(httpServer).on('connection', (socket)=>{
            console.log("inside socket conection");
                    console.log('HELLO BISH')
                    // console.log(data.text)
                    socket.emit("hello_back", data);

Sockets are working fine on the Web but while connecting these from Flutter App, Getting a connection timeout error. Can anyone suggest to me what can be the issue here?

Deployed the Application both on Heroku & production. Also, checked on HTTP & HTTPS the error is the same for both.

Please help.