How many sessions of Juvelook Volume are needed to be satisfied with under-eye hollowness improvement?

I have sunken under-eyes, which makes my dark circles look worse, so I am looking into the Juve Look Volume procedure. However, after searching, I found many reviews stating that it is not a one-time treatment but requires multiple sessions.

I'm not sure how many sessions I need to feel my under-eye area plumping up, and I'm also curious if the effects vary from session to session.

It would be very helpful if those of you who have received the treatment could honestly share how many sessions it took to see satisfactory changes, the duration of the results, and whether additional treatments are necessary.