Connect to existing AWS resources
Amplify client libraries provide you with the flexibility to directly connect your application to AWS resources, regardless of whether you choose to set up an Amplify backend environment or manually configure individual AWS services, such as AWS AppSync, Amazon Cognito, Amazon S3, and more.
If you configured AWS resources outside of an Amplify backend, you can still use the Amplify libraries to connect to them by following the instructions provided:
Connect to Cognito resources using Amplify Auth's client library