I think it is highly unlikely that Napoli can win at Camp Nou, Napoli is a team totally in the budget, a distant memory of the Napoli Italian champion last year. Although Barcelona has not done its best championship of the last 20 years, it can count on very strong and unpredictable players. Statistics in hand for me a victory of Napoli remain unlikely but not impossible, in football everything can happen
However, we don't know how the match will turn out in the second leg. although as we can see, also referring to the betting market, the probability of Napoli is very small. however, we also have to remember that the results will be determined later when this battle is held. I remember very well last season, at that time Barcelona had a fairly high probability of playing against Inter. however, the result was that the match ended with a score of 3-3 in the second leg and Barcelona failed to advance to the next phase.
In the round of 16 second leg against Napoli, it looked like a similar situation to the previous season. Barcelona is superior even though their performance is unstable. the advantage of playing at Camp Nou at home, plus several players have recovered from injuries. Barcelona has odds @1.66, while Napoli @5.20. there is a gap between these two teams, especially in the first leg, the match ended in a draw. so, it is very natural that Barcelona has a higher probability of winning this match.
even so, Napoli will try to work hard to provide resistance to the home team. after all, Napoli has a chance, even though the probability is very small. Let's just wait, after all the match will be held on February 13th. there are still things that can be improved by Barcelona and Napoli.