On the Choose domain page, choose the AWS storage service that you want to use to store and access your data over the selected protocol:
Choose Amazon S3 to store and access your files as objects over the selected protocol.
Choose Amazon EFS to store and access your files in your Amazon EFS file system over the selected protocol.
Choose Next.
In Configure additional details, do the following:
For CloudWatch logging, choose one of the following to enable Amazon CloudWatch logging of your user activity:
Create a new role to allow Transfer Family to automatically create the IAM role, as long as you have the right permissions to create a new role. The IAM role that is created is called AWSTransferLoggingAccess.
Choose an existing role to choose an existing IAM role from your account. Under Logging role, choose the role. This IAM role should include a trust policy with Service set to transfer.amazonaws.com.
For more information about CloudWatch logging, see Log activity with CloudWatch.