Update app.py

app.py

@@ -18,6 +18,10 @@ from langchain.prompts import PromptTemplate
 from langchain.chains import RetrievalQA
 from langchain.chains.conversation.memory import ConversationBufferWindowMemory
 from langchain.agents import Tool, initialize_agent
+from huggingface_hub import login
+
+# Check if the token is already set in the environment variables
+hf_token = os.environ(["HF_TOKEN"])