Where i can found routes of webpages and desktop module routes?

I mean url links and how can i change them?

Routes for web pages are automatically set based on the title. You can change by updating parent_website_route and page_name properties.

I i added testing.html where i can added path to display content in testing.html i was place my html page in pages folder

I have same requirement , How i can achieve that ?

check the webiste/router.py file . you can tweak the method and achieve customized routing in there.