Trying to download a video then convert the video to an mp3, I end up getting a Attribute error

Question

I get a 'streams has no endswith attribute'

# Download function MP3
def download():
    try:
        mp3_file = "audio.mp3"
        url = YouTube(str(link.get()))
        video = url.streams.first()
        VideoClip = VideoFileClip(video)
        audioclip = VideoClip.audio
        audioclip.write_audiofile(mp3_file)
        audioclip.close()
        VideoClip.close()
        mp3_file.download(Path.home() / "Downloads")
        Label(root, text = "Downloaded",).place(relx = .5, rely = .6, anchor = CENTER)
        link_enter.delete(0,END)
    except AttributeError:
        print("No")

What's supposed to happen is I click a button and the mp4 is converted to mp3 and downloaded, but I get the AttributeError