iamRole
The role assigned to an Amazon EC2 instance configured with a Systems Manager Quick Setup host management configuration or the role assigned to an on-premises managed node.
This call doesn't return the IAM role for unmanaged Amazon EC2 instances (instances not configured for Systems Manager). To retrieve the role for an unmanaged instance, use the Amazon EC2 DescribeInstances
operation. For information, see DescribeInstances in the Amazon EC2 API Reference or describe-instances in the Amazon Web Services CLI Command Reference.