Where can I find more details for i-tutorials problem 10.1?

Hi, I’m an undergraduate student in the Department of Mathematics, A.U.TH.
I’m starting a project for problem 10.1 Coupling NGSolve and NGSpice from i-tutorials and I need some details. I would like to ask what exactly does it solve (what is the problem), where can I find more info for the code etc.

Thanks.