Update main.py

main.py

@@ -396,7 +396,7 @@ async def presentation_chat(query: PresentationChatModel, background_tasks: Back
     # Collect the entire response
     full_response = ""
     async for chunk in response_stream.body_iterator:
-        full_response += chunk.decode()
+        full_response += chunk
 
     # Extract the Marp presentation content
     marp_content = extract_data_from_tag(full_response, "marp_presentation")