我正在尝试为我的Discord bot做一个测试命令，这样它就可以加入VC并播放我设置的URL。我遇到了代码问题，请帮助我。
代码如下：

# test vc join
@bot.command()
async def test_join(ctx):
    url = adhan_media
    guild = ctx.guild
    channel = ctx.author.voice.channel
    try:
        await channel.connect()
        await ctx.send(f"I can join voice channels!")
        print(f"Successfully joined voice chanel {channel} in {guild}")
        player.play(url)
    except Exception as e:
        await ctx.send(f"Voice chat test unsuccessful.")
        print(f"Could not join voice channel {channel} in {guild} due to the following error: {e}")
    if channel == None:
        await ctx.send(f"You are not in a voice channel!") 
        print(f"Bot did not join voice channel in {guild} due to {ctx.author} not being in voice chat.")

这是我得到的错误：
discord.ext.commands.errors.CommandInvokeError: Command raised an exception: NameError: name 'pynacl' is not defined
我期望它加入语音聊天并播放提供的网址，但它没有。