Missing doc about how to share backend across different apps

[hangoocn]

Describe the content issue:
I have created a react vite app using Amplify gen2, and want to create a gen 2 amplify flutter app using and share the same backend e.g. auth, storage with the react app.

It has clear doc about how to do it in gen 1, but there seems no exact doc for gen 2. The closest doc is share resouces across branches, is that same as share across apps?

And the docs is more about deployment, for local development, how do I make two apps consumes the same sandbox?

Thanks for your answer!