When am I supposed to add lime juice to the semifreddo? Its not written in any of the steps except the coulis

I just put this in the freezer, and I'm very much looking forward to tasting it. However, I've read the recipe multiple times, and cannot find a use for the 2 tsp of lime juice, listed as an ingredient in the semifreddo portion of the recipe. When exactly is it supposed to be added?
Thanks