This extension uses DLib or InsightFace to perform various operations on human faces.
The most obvious is to calculate the similarity between two faces. The best way to evaluate generated faces is to first send a batch of 3 reference images to the node and compare them to a forth reference (all actual pictures of the person). That will give you a baseline number that you can use to compare to generated images.
You need to install either InsightFace or Dlib (or both).
For DLIB download Shape Predictor, Face Predictor 5 landmarks, Face Predictor 81 landmarks and the Face Recognition models and place them into the dlib directory.
Precompiled Dlib for Windows can be found here.
The extension also supports AuraFace that is a free alternative to InsightFace. Download all the files and place them under models/insightface/models/auraface/