Get all html code of one app


I am starting to work with Dash and I have thought that would be useful for me get all html code to create a diagram of structure of the app with the graphviz library (I want to konw about it because I have not created).

How can I get all html code if my app is made with several pages (each page is .py file)?

what do you suggest?

I leave an example image of what I would like to do although I want each element to be more self-descriptive

Thank you in advance