We’re working on a feature to embed some of our Gynzy tools on your website.
I created this post to test our embedded tools (see example below).

Unfortunately it’s not possible to insert iFrames in a WordPress post by default.
That’s why I used this plugin: https://wordpress.org/plugins/iframe/

When the plugin is activated, use this shortcode to insert the Gynzy tool: 

UPDATE:
it’s possible to insert iframe-code in textmode.
The tool below is inserted in textmode, without the use of a plugin.