Overriding role arn in existing kubeconfig from aws cli/kubectl cli

Question

I want to use existing kubeconfig but with different role arn to use iam authenticator in aws eks. I want to login cluster through automation but IAM authenticator is not updating role arn in kubeconfig. That is the reason I'm looking out ways to pass role arn dynamically but all other things from existing kubeconfig file.

Any help much appreciated