How to make a centered invisible menu

Hi everyone!
I am trying to make this kind of menu in the nicest way possible. I attach the menu layout I am trying to make.

  • When Scrolling down, a different navbar will appear (but this time with a background), so the menu is always visible.

  • I tried to use the “J7 Beaver Header Footer Template”. But for some reason the “template Options” do not appear. So I cannot make everything like in the
    tutorials. Photos below :

Any idea of what’s the best way to make this menu?

Thanks a lot in advance.