How do I add a button to the mobile site?

I have a "shop" button up in the right hand corner of my website and it shows up on my desktop site but it does not show up on the mobile site. 

How do I get the shop button on the mobile site?

https://ksthesauce.com/

Thank you!

There is a "Shop" button on the mobile version for me, but it's in the top lefthand corner. I actually don't see it on desktop, but this might just be a positioning issue. In the editor, click on mobile view, try repositioning the button, saving and reloading. It won't impact the desktop layout and should solve the issue.

You can use this code to Website Tools > Custom CSS

/* Show button on mobile */
@media screen and (max-width:991px) {
  .header-actions.header-actions--right, .header-actions-action.header-actions-action--cta {
    display: flex !important;
}
.header-title-nav-wrapper {
    flex: 1 0 30% !important;
}
    .showOnMobile {
    display: none !important;
}
}