How to set a mobile menu

Hi

Ive been searching the forums for this but cannot find an answer.

Im looking to have a main menu on my mobile that’s different from the desktop version.

I want to have my own custom mobile site so have the automatic version of the mobile site switched off. I have the site set to responsive and I have the ‘Home Setup’ set to Menu List.

I have a menu created called ‘Mobile’ with 3 items, the other menu on have two. I dont seem to have any sort of tickbox at the bottom of the screen to allocate this to mobile, only Top Navigation, Main Navigation & Footer Links.

How can I replace the main navigation menu on my mobile to this one?

Alternatively, the thing Im trying to do is add a search bar or option to every screen. Ive got it built into the search bar on my desktop site but it disappears in the mobile version, so I wanted to add a link on my menu to a search page.

Any ideas?