Where is the navmenu-v element?

Question

Python

I can't find the navmenu-v element on the site https://www.site-do.ru/doSite/doSite.php.
I wanted to see how the side menu works, but I did not find the navmenu-v element in the code, which is used in the start line
of the ul list in the call to document.getElementById("navmenu-v").style.display="block";.
Why does the side menu work and this element is not in the document?

Answer 1

I wanted to see how the side menu works, but I did not find the navmenu-v element in the code that is used in the line

So he is not there. That is why the following errors are thrown in the console:
The menu works on pure CSS, without scripts.