Different Menu for Mobile version (Showcase Theme)

I created a new menu navigation menu titled Main Menu Mobile (handle=main-menu-mobile). How can I add this to my theme so on mobile it can show a different menu than desktop? Someone on this discussion form given below code that can be used but in showcase theme I couldn’t find that code to replace.

{% for link in linklists.main-menu.links %}

… with:

{% for link in linklists.main-menu-mobile.links %}

In showcase theme or header liquid file I can not find first one link. So I cant replace but My theme auto change the menu to burger menu below 1100px.

Here is my store link. Not password protected. https://uptimefabrics.myshopify.com/