The IFrame module is used as a way to house an external web page into the platform.
Only certain web pages will Iframe into the platform and there is nothing we can do to try and make a page Iframe if it will not - this is entirely down to the way the original webpage is configured.
To check whether a url will Iframe you will need to add an Iframe module.
You can name the Iframe whatever you like and then copy and paste the url into the module.
Remember to include either https or http.
If the url will not work then the CMS will alert you at this stage.