Is it possible for a libero to score point during a volleyball match?
Yes. There is nothing in the rules, in particular Rule 19 "The Libero Player", which says that a libero cannot score points.
The libero cannot hit the ball
This is incorrect. Quoting from Rule 188.8.131.52:
[The Libero] is not allowed to complete an attack hit from anywhere [...] if at the moment of the contact the ball is entirely higher than the top of the net.
(my emphasis) i.e. the libero can hit the ball, so long as it's done from below the height of the net.
There is any exemple with the libero with points at the end of the match?
Yes - you can see some examples of Japan's libero, Arisa Satō, scoring points in this YouTube video.