I want to implement GoRouter package for Routing in my existing Flutter mobile app(configuring for web). I have multiple modules with multiple screens which are currently handled by Navigator.push. How can I create nested GoRoutes for each of my module?

I have an existing flutter app for mobile using provider package and which I am configuring for web. So I want to implement GoRouter package for Routing.
I have used providers through the app. Registration flow is divided into 3 screens. How can I share my notifier object between the screens.

I would like to create a workflow with GoRouter in my Flutter web app without changing the URL, but I can’t manage to do it. Even with using ShellRoute. My router is as following:

I just migrated my go_router package from 12.1.3 to 13.2.4.