How to use this

Question

https://code.sololearn.com/WN5tz0FzW9cU/?ref=app

Answer 1

It looks like everything comes down to this part:
<iframe src="https://sololearn.chikuaicode.in/codes/multi_page/first.html"
title="Multi_Page Web Development"></iframe>

I guess the only other thing you can do is watch his video on how he did it.