Create navigation bar at the bottom of my mobile view for a shopping cart icon. (brine)

I am trying to add a navigation bar at the bottom of my mobile view for the shopping cart icon. I am currently using a template in the brine family and I was told this template doesn't support a navigation bar like this. I am wondering if there is code I can add to create this? If not, is there a way to add a shopping cart link in my primary navigation dropdown?

please see attached image for reference.