Adding a component above a single blog post and iframe HTML issue?

This is the page link on my site - www. learnelectronicsindia .com/ python-chapter-2

I have added the horizontal bar using HTML element on the Wix site and added a simple Horizontal scroll(or Pagination) by copying the code from internet. The code works fine and the Horizontal scroll is also displayed properly but when I click on any button on the scroll bar then it open the page inside the scroll bar area instead of loading on the whole page.

I am not a very good programmer but understand a little basic of HTML now though that doesn’t help me solve the issue and that is why I would need your help. Please suggest me, how do I do it?

Also, the code I added using the HTML component for one blog post automatically appears for all the other blog posts too. I want to know, if there is a solution for this issue?

Thanks in advance.
Jainesh Rathod