How eksctl assume a CloudFormation execution role?

I created an EKS cluster using CloudFormation template, so a CloudFormation execution role is used to create the EKS cluster. Then I want to run eksctl to create service account from my terminal, however, it failed due to unauthorized. I think that this is because eksctl is not able to assume the CloudFormation execution role yet. In this case, how to let eksctl to assume a role?