well that looks like a crappy version of it or a very basic version.
I can not check mint ATM but if you want software source code on ubuntu you just tick the source code box on the first tab in the software sources app.
the software sources application is called software-properties-gtk and can be run from the command line with a sudo.
try that first, or the manual way next.
the software source repos if you want to add them manually all start with deb-src. so if you want just add them to the end of your /etc/apt/sources.list file you could just copy a line and replace the deb at the start of the line with deb-src.
here is the main one though.
fiesty-security main restricted universe multiverse
I hope the gui works out though.
if it is not present try looking for it in synaptic.
I will now leave you with the mess i created.