Update app.py

app.py

@@ -248,7 +248,7 @@ with gradio.Blocks(title="ChatGPT", css=css) as demo:
                         chat_log = gradio.State()
                         with gradio.Box():
                             chat_log_box = gradio.Markdown(label='chat history')
-                        chat_input_role = gradio.Textbox(lines=1, label='role', value='user')
+                        chat_input_role = gradio.Dropdown(lines=1, label='role', choices=['user', 'system', 'assistant'], value='user')
                         chat_input = gradio.Textbox(lines=4, label='input')
                 with gradio.Row():
                     chat_clear_history_btn = gradio.Button("clear history")