It's probably not helpful, if you dont use a DAW, but I would recommend exporting the vocal as a wav-file, importing it into a DAW (Studio One, Cubase, Reaper etc), and then use an equaliser to cut certain frequencies. It seems to help to cut 200
Sorry I accidentally posted an unfinished reply, I meant to say that you could cut around 500-2000 hz or try to experiment, until the voice sound less nasal.