updating app.py

app.py

@@ -162,7 +162,10 @@ async def start_chat():
     """
 
     ### BUILD LCEL RAG CHAIN THAT ONLY RETURNS TEXT
-    lcel_rag_chain = 
+    lcel_rag_chain = (
+        {"context": itemgetter("query") | hf_retriever, "query": itemgetter("query")}
+        | rag_prompt | hf_llm
+    )
 
     cl.user_session.set("lcel_rag_chain", lcel_rag_chain)