How to update layout of app based on the dropdown selection

I am trying to implement a dash app which the application’s layout will be updated based on the selection of dataset in the dropdown menu. However, I am not able to do it even when call the layout function explictly in the callback.

Is there anyone can point out how to do it?

Thanks in advance.

Hello! What are you trying to change about the layout? And what is the format of your layout function?

There’s a bit of information on callbacks modifying layout here.