Missing doc about how to share backend across different apps

**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 ](https://docs.aws.amazon.com/amplify/latest/userguide/reuse-backends.html) about how to do it in gen 1, but there seems no exact doc for gen 2. The [closest doc](https://docs.amplify.aws/nextjs/deploy-and-host/fullstack-branching/share-resources/) 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!