Describe the content issue:
When adding custom resources like REST APIs in Gen2, it was not clearly explained that those need to be explicitly configured -- you cannot just call Amplify.configure(outputs) and expect the custom APIs, etc. to be added to your Amplify config.

In the case of custom REST APIs, this issue will manifest with thrown error API name is invalid when trying to call it.

Please update the docs to explain how this works more clearly, it does not stand out in the example at the bottom of this page.

URL page where content issue is:
https://docs.amplify.aws/react/build-a-backend/add-aws-services/rest-api/set-up-rest-api/

https://github.com/aws-amplify/docs/edit/main/src/pages/%5Bplatform%5D/build-a-backend/add-aws-services/rest-api/set-up-rest-api/index.mdx