Help using iframe

I’ve seen and read my posts concerning this topic, nevertheless I haven’t found any concrete answer as to how I can achieve this. I would like to use an iFrame to do what was done with the following app:

I want to use a personalized domain like that website. Any ideas on how I can get this done?
Also in that example, are they paying for the domain “” or is there a way to get that done without paying for a domain?
Finally, can this be done with an app that requires signing in?

Thank you

First, you need to buy a domain and hosting. Point domain to your host. Then you can use this code to make an index.html file then upload it to your hosting.
It can make your web fully responsive with Appsheet.

<html lang="en" class="no-js">
      <meta charset="utf-8">
      <meta name="viewport" content="width=device-width,initial-scale=1.0">
      html body {width: 100%;height: 100%;padding: 0px;margin: 0px;overflow: hidden;font-family: arial;font-size: 10px;color: #6e6e6e;background-color: #000;} #preview-frame {width: 100%;background-color: #fff;}</style>
      <script src=""></script>
         var calcHeight = function() {

         $(document).ready(function() {

         $(window).resize(function() {
         }).load(function() {
      <iframe id="preview-frame" src="**Your Appsheet Url**" name="preview-frame" frameborder="0" noresize="noresize">