Update app.py

app.py

@@ -1,6 +1,6 @@
 import os
 import time
-from typing import Union, LiteralString
+from typing import Union, AnyStr
 from urllib.parse import urlparse, parse_qs
 import textwrap
 import streamlit as st
@@ -26,7 +26,7 @@ def find_audio_files(path, extension=".mp3"):
     return audio_files
 
 
-def youtube_to_mp3(youtube_url: str, output_dir: str) -> Union[LiteralString, str, bytes]:
+def youtube_to_mp3(youtube_url: str, output_dir: str) -> Union[AnyStr, str, bytes]:
     ydl_config = {
         "format": "bestaudio/best",
         "postprocessors": [