Create a custom toast message and respond to the activation event recieved from the user selection.

toast.js

(function () {
	"use strict";

	function createToast(message, imgUrl, imgAlt) {
	    // Namespace: Windows.UI.Notifications
	    if (typeof Windows !== 'undefined' &&
	        typeof Windows.UI !== 'undefined' &&
	        typeof Windows.UI.Notifications !== 'undefined') {
	        // Setup variables for shorthand
	        var notifications = Windows.UI.Notifications,
	        templateType = notifications.ToastTemplateType.toastImageAndText02,
	        templateContent = notifications.ToastNotificationManager.getTemplateContent(templateType),
	        toastMessage = templateContent.getElementsByTagName('text'),
	        toastImage = templateContent.getElementsByTagName('image'),
	        toastElement = templateContent.selectSingleNode('/toast');
	
	        // Set message & image in toast template
	        toastMessage[0].appendChild(templateContent.createTextNode(message || 'Demo message'));
	        toastImage[0].setAttribute('src', imgUrl || 'https://unsplash.it/150/?random');
	        toastImage[0].setAttribute('alt', imgAlt || 'Random sample image');
	        toastElement.setAttribute('duration', 'long');
	        toastElement.setAttribute('launch', '{"type":"toast","code":"info"}'); // Optional Launch Parameter
	
	        // Add actions
	        var actions = templateContent.createElement('actions');
	        templateContent.firstChild.appendChild(actions);
	
	        // Create an input box
	        var input = templateContent.createElement('input');
	        input.setAttribute('type', 'text');
	        input.setAttribute('title', 'Reply with');
	        input.setAttribute('id', 'textReply');
	        actions.appendChild(input);
	
	        // Create a yes button
	        var btnYes = templateContent.createElement('action');
	        btnYes.setAttribute('content', 'Yes');
	        btnYes.setAttribute('arguments', 'yes');
	        btnYes.setAttribute('launchType', 'foreground');
	        actions.appendChild(btnYes);
	
	        //Create a no button
	        var btnNo = templateContent.createElement('action');
	        btnNo.setAttribute('content', 'No');
	        btnNo.setAttribute('arguments', 'no');
	        btnNo.setAttribute('launchType', 'foreground');
	        actions.appendChild(btnNo);
	
	        // Show the toast
	        var toast = new notifications.ToastNotification(templateContent);
	        var toastNotifier = new notifications.ToastNotificationManager.createToastNotifier();
	        toastNotifier.show(toast);
	    } else {
	        // Fallback
	    }
	}
	
	if (typeof Windows !== 'undefined' &&
	    typeof Windows.UI !== 'undefined' &&
	    typeof Windows.UI.WebUI !== 'undefined') {
	    Windows.UI.WebUI.WebUIApplication.addEventListener('activated', function (args) {
	        var activation = Windows.ApplicationModel.Activation;
	
	        if (args.kind === activation.ActivationKind.toastNotification) {
	            console.log(args.argument);
	            console.log(args.userInput.textReply);
	        }
	    });
	}
	
	createToast();
	
})();

Getting Windows undefined.

if(Windows !== 'undefined' &&      
^
                                 
ReferenceError: Windows is not defined          

OS : win10 [Version 10.0.17763.973]