from pytubefix import YouTube
from pytubefix.cli import on_progress


url = "https://www.youtube.com/watch?v=PKHQuQF1S8k"

yt = YouTube(url, on_progress_callback=on_progress)
print(yt.title)

ys = yt.streams.get_audio_only()
ys.download(mp3=True)  # pass the parameter mp3=True to save in .mp3