If you look at the notes for the recipe, they say that "cured pancetta" is an acceptable substitute for "fresh pancetta", but "smoked pancetta or bacon" are unacceptable.
Based on that, I think by "fresh pancetta" they just mean pork belly. If you play around with Google Translate, you'll see that it thinks "pancetta" translates to "bacon", but "pancetta di maiale" translates to "pork belly". "Maiale" just means "pig", so there's clearly some room for things to be lost in translation, but I can't think what else they could mean when they specify "fresh".