Update app.py

app.py

@@ -128,7 +128,7 @@ with st.sidebar:
     selected_model = st.sidebar.selectbox('Choose a LLM model',
                                            llm_list,
                                              key='selected_model',
-                                             index = None)
+                                             index = 1)
 
     temperature = st.slider("Temperature: ", 0.0, 1.0, 0.5, 0.1,
                             help=("Controls the creativity of responses.\n"