Toggle Button Container

Don’t Undertand this explanation…
“The CSS selector of an HTML element which will contains the toggle menu button on mobile devices. The toggle button will be injected into this element via Javascript.”

The plugin will do it automatic or i most do it? How do i do this? No documentation for this.

I want to disable the native and create a new one, but i don’t undertand how i will trigger this. can you explain it to me?