It is easy to tell that you have an accent . You are emphasizing on the 'T" for example . The pronunciation of ''r' is not adequate. In general the accent is very obvious ,except for the words '' o sole mio ' . Those are pronounced correctly ! If you want to improve the pronunciation just for this song , you will need to listen to it more often and repeat ! In boca al luppo :)

You have a beautiful voice, I think isn't so important to pronounce the words perfectly. I'm Italian but I'm not able to speak neapolitan, it is a dialect. I send to you a video https://youtu.be/8TcY7_wiFhs . with the lyrics of O sole mio , so you can listen and sing. Maybe you know already this so I send to you another song that I like, there are the lyrics in Italian an in English https://youtu.be/jhd-xFASCrM I hope you like it and that you will do a video on YouTube with this song !!!

This a Neapolitan song, it is not easy at all to have a perfect pronunciation for a non Neapolitan. So your performace is very good!