fix f print

app.py

@@ -80,7 +80,9 @@ def chat_gen(message, history, return_buffer=True):
         
         buffer += "I use the following websites data to generate the above answer: \n"
         for doc in retrieved_docs:
-            buffer += f'{doc['metadata']['source']}\n'
+            buffer += f"{doc['metadata']['source']}\n"
+        
+        yield buffer
     else:
       passage = "I am sorry. I do not have relevant information to answer on that specific topic. Please try another question."
       buffer += passage