Update app.py

app.py

@@ -73,6 +73,7 @@ def chatbotCustom(input):
     retriever = VectorIndexRetriever(
         index=index,
         similarity_top_k=10,
+        response_mode="tree_summarize",
     )
 
 # configure response synthesizer
@@ -85,7 +86,7 @@ def chatbotCustom(input):
         node_postprocessors=[SimilarityPostprocessor(similarity_cutoff=0.7)],
     )
 
-    response = query_engine.query(input, response_mode="tree_summarize")        
+    response = query_engine.query(input)        
     return response.response
 
 #def chatbotGPT(input):