To use IAM roles for service accounts in your cluster, you must create an OIDC identity provider in the IAM console
eksctl version
If your eksctl version is lower than 0.5.1, use Installing or Upgrading eksctl in the user guide
eksctl utils associate-iam-oidc-provider --cluster eksworkshop-eksctl --approve
If you go to the Identity Providers in IAM Console, you will see OIDC provider has created for your cluster