Added lines 5 & 6

from getpass import getpass
HUGGINGFACE_API_TOKEN = getpass()

app.py

@@ -1,8 +1,12 @@
 import gradio as gr
 import os
 
+from getpass import getpass 
+HUGGINGFACE_API_TOKEN = getpass()
+
 os.environ["HUGGINGFACE_HUB_API_TOKEN"] = HUGGINGFACE_HUB_API_TOKEN
 
+
 from langchain_community.document_loaders import PyPDFLoader
 from langchain.text_splitter import RecursiveCharacterTextSplitter
 from langchain_community.vectorstores import Chroma