How to Add HTML (custom widgets) to a page or post:
1. Login to your WordPress dashboard.
2. In the navigation menu click the Pages or Posts link, depending which one you want to add the widget to. For the purpose of this article we clicked Posts.
3. Now, click the page or post that you want to edit.
4. Click the Text tab.
5. You will then see the text of the page or post and you can enter the HTML. Copy and paste the widget code (from: https://designfiles.co/settings/widget) into the post.
6. Click Update to save your changes.