How to add publications on Academic website in Github?

I’m building my website with the Academic theme on Github. I forked the github repository and started adapting everything ( I am already happy about the result:

Now I want to manually add publications. I tried some stuff, but it doesn’t work. I read I have to use this command (hugo new --kind publication publication/), but I have no idea how to begin with this (which program?, etc). I installed powershell and Hugo. But from there I’m stuck. How to proceed from there?