Secondary Menu Below Primary Menu on Home Page of GP Target Theme

Hello everyone, I really like using GP and have used it to develop a couple of different websites. I recently installed the GP Target theme on my website and am currently making tweaks to get it looking how I want it. Can somebody assist me with showing the secondary menu (store menu) beneath the primary menu on the website's home page?

Main Page: https://geordiegadgets.co.uk
Store Page: https://geordiegadgets.co.uk/shop-2/

I have tried to do this by checking the box under the menu but nothing is working is there any way to add the secondary menu under the primany menu on the home page using a function?