Profile Authentication with AWS SigV4 Signer for Dart

Hi,

I am not sure on how to handle authentication using AWS SigV4 Signer for Dart. Copying the keys from the aws console and copying them into env vars is not working well for me because they are only have short term validity. Do you know how the AWSCredentialsProvider.profile() constructor is supposed to work? I have completed all these steps with aws cli and have all the files in ~/.aws. When I run flutter with iOS Simulator I am getting: Unhandled Exception: InvalidCredentialsException: Could not load credentials for profile "dev"