Update app.py

app.py

@@ -18,9 +18,8 @@ button:hover { background-color: #a01010; }
 def get_response(message, chat_history, model_choice, api_key):
     reply =generate_answer(message,model_choice,api_key)
 
-    chat_history.append((message, reply))
+    chat_history.append([message, reply])
     return reply, chat_history
-
 # Gradio app
 with gr.Blocks(css=custom_css) as app:
     with gr.Row():