Ember with Code Sandbox

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>

<br>

<p data-height="167" data-theme-id="0" data-slug-hash="PaXjzv" data-default-tab="css,result" data-user="karthikadevi" data-embed-version="2" data-pen-title="Testing Embedding CodePens" class="codepen">See the Pen <a href="https://codepen.io/karthikadevi/pen/PaXjzv/">Testing Embedding CodePens</a> by KarthikaDevi (<a href="https://codepen.io/karthikadevi">@karthikadevi</a>) on <a href="https://codepen.io">CodePen</a>.</p>

twiddle.json

{
  "version": "0.14.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "2.18.2",
    "ember-template-compiler": "2.18.2",
    "ember-testing": "2.18.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}