Spectron: Unable to interact with elements on electron application after launching the application

I am able to launch the electron app with Spectron but not able to perform any actions on it.

OS: Windows 8.1

Node Version : 10.16.0

Spectron: 3.8.0

var Application = require('spectron').Application;
var chai = require('chai');
var chaiAsPromised = require('chai-as-promised');
const SearchPage = require('./page-objects/search.page');
const assert= require('assert');

describe('Test Suite', function () {
    this.timeout(20000);
    beforeEach('Start Application',  function () {
        this.app = new Application({
            path: 'path of .exe file located', // Ex: D:\\Foldername\\filename.exe
            requireName:'electronRequire',
            env: {
                NODE_ENV: 'test'
            }
        });
        chai.should();
        chai.use(chaiAsPromised);
        chaiAsPromised.transferPromiseness = this.app.transferPromiseness;
        return  this.app.start()
    });

    afterEach(() => {
        if (this.app && this.app.isRunning()) {
            return this.app.stop();
        }
    });

    it('Sign In, function () {
         return this.app.client.
            .pause(20000) //waiting for login window
            .setValue(SearchPage.username, 'username').pause(1000)
            .setValue(SearchPage.password, 'password').pause(1000)
            .click(SearchPage.loginButton);
    });         

});

Package.json file:

{
  "name": "spectron-test-framework",
  "version": "1.0.0",
  "description": "Test Framework for Electron Desktop Application",  
  "main": "index.js",
  "scripts": {
    "test": "mocha --timeout 20000",
  },
  "author": "Tester",
  "license": "ISC",
  "devDependencies": {
    "webdriverio": "^4.10.2",
    "chai": "^4.1.2",
    "chai-as-promised": "^7.1.1",
    "electron": "^2.0.2",
    "mocha": "^5.2.0",
    "mochawesome": "^3.0.2",
    "spectron": "^3.8.0"

  }
}

I am unable to interact the elements and seeing error as

1) Test Suite Sign In: Error: Timeout of 20000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (D:\spectron-example\Spec.js)

Even if I am increasing the timeout still seeing this timeout error.

How to fix this issue?

And my Questions are

Can we Start writing automation script without development code base ? because in most of the sample tests I have seen automation script is available in test folder of development code.

I have .exe while launching which I am able to see application being launched but not able to perform actions. Does .exe file needs to be provided to QA for automation with any specific packages and options enabled/disabled.

What are the Ideal Electron, Spectron, Nodejs, Wdio, Mocha compatible versions to work together?

Thanks In Advance.