Yes, Hapax is definitely a goth band because most of their albums belong to the Gothic Rock and Darkwave genres, which are among the core subgenres of goth music. Albums like Stream Of Consciousness, Cave, and Monade are examples of their goth sound.
Some of the other goth artists that are similar to them are Twin Tribes, Skeleton Hands, and Silver Tears.
Hapax is located in Italy, Naples, active in 2014 — 2023. You can find more information about Hapax on their GothDB band page.