added so that enter will submit message

app.py

@@ -284,5 +284,23 @@ with gr.Blocks() as demo:
                 ],
                 outputs=[chat_box, msg] 
             )
+            msg.submit(
+                fn=respond,
+                inputs=[
+                    msg,
+                    chat_box,
+                    language,
+                    chatbot_mode,
+                    destinations,
+                    trip_length,
+                    trip_unit,
+                    trip_season, 
+                    luggage_types,
+                    luggage_size,
+                    food_prefs, 
+                    activity
+                ],
+                outputs=[chat_box, msg]
+            )
 
 demo.launch(debug=True)