Why is iframe not loading css and javascript?

Question

CMS

There is a separate page with the test and only with it (jQuizer), it needs to be loaded on another page. I tried to just put it - it turns out there is no adaptability, and there is no desire to make it adaptive. I found an iframe on another site that uses it, I tried it and styles and javascript are not loaded. I don’t understand how it loaded ... I only load html.
What can be done?