Update app.py

app.py

@@ -9,8 +9,11 @@ from langchain.memory import ConversationBufferMemory
 from langchain.chains import ConversationalRetrievalChain
 from htmlTemplates import css, bot_template, user_template
 from langchain.llms import HuggingFaceHub
+import os 
 # from langchain.callbacks import get_openai_callback
 
+hub_token = os.environ["HUGGINGFACEHUB_TOKEN"]
+
 def get_pdf_text(pdf_docs):
     text = ""
     for pdf in pdf_docs:
@@ -41,7 +44,7 @@ def get_vectorstore(text_chunks):
 
 def get_conversation_chain(vectorstore):
     # llm = ChatOpenAI(model_name="gpt-3.5-turbo-16k")
-    llm = HuggingFaceHub(repo_id="google/flan-t5-xxl", model_kwargs={"temperature":0.5, "max_length":512})
+    llm = HuggingFaceHub(repo_id="google/flan-t5-xxl", huggingfacehub_api_token=hub_token, model_kwargs={"temperature":0.5, "max_length":512})
 
     memory = ConversationBufferMemory(
         memory_key='chat_history', return_messages=True)