If you want to create menu which is like on this page and always in the sidebar position check these settings.

You should select the Tree navigation type, Left sidebar menu positioning and Auto Open menu on every page load in the Module settings / Basic Parameters.

Customize item style step 1
Navigation type and menu positioning

After that, you should set the Animation Parameters / Sidebar Animations to reduce with.

Customize item style step 2
Animation parameters

There is nothing left behind, check your vertical menu on the frontend.