Having problem's with os module compatibility with streamlit app hosted

This is my function :

def speak_text(text, voice, rate=150):
  engine = pyttsx3.init()

  print("TEXT : ", text, '\n')
  print("VOICE : ", voice, '\n')

  engine.setProperty('voice', voice)
  engine.setProperty('rate', rate)


  download_dir = 'dir_mp3'
  os.makedirs(download_dir, exist_ok=True)

  file_path = os.path.join(download_dir, "my_audio.wav") 
  
  engine.save_to_file(text, file_path)
  engine.runAndWait()
  engine.stop()

  return file_path

`
And when I call this function in my main function :

     if genders=="Male":
        bytes_path = speak_text(story, voices[0])
    else:
        bytes_path = speak_text(story, voices[1])


    with open(bytes_path, "rb") as mp3_file:
        aud_bytes = mp3_file.read()
    with open(bytes_path, "rb") as mp3_file:
        aud_bytes = mp3_file.read()

I get an error saying that file or directory doesnโ€™t exists, but when I manually print โ€˜bytes_pathโ€™ variable I get complete path of .wav file.

Note that code is uploaded on Github and while deploying my app Iโ€™m getting these logs .

Is there anything wrong with my code ?

Thanks
I Appreciate your response