AttributeError with ffmpeg

I’m trying to make a command with nextcord where the bot would join the vc I’m currently in and speak a message, but it gives me this error:

AttributeError: ‘FFmpegOpusAudio’ object has no attribute ‘_process’

from gtts import gTTS
@bot.command(name='tts', description='TALK')
async def tts(ctx, *args):
  text = ' '.join(args)
  if != None:
      vc = await
      vc = ctx.voice_client
    sound = gTTS(text=text, lang='en', slow=False)"tts-audio.mp3")
    source = await nextcord.FFmpegOpusAudio.from_probe("tts-audio.mp3",method="fallback")