Invalid Service in Action

MSK has released a new feature. Basically, kafka client can authenticate and authorize using IAM. Link is below:
https://aws.amazon.com/about-aws/whats-new/2021/05/introducing-iam-access-control-amazon-msk/

I tried out this by following the official documentation,
https://docs.aws.amazon.com/msk/latest/developerguide/iam-access-control.html#configure-clients-for-iam-access-control

But when I try to create policy in step 3 i.e. Create Authorization policies, I get the following error
Invalid Service In Action: The service kafka-cluster:Connect specified in the action does not exist.

When I checked the IAM actions, resources and conditions for MSK from https://docs.aws.amazon.com/service-authorization/latest/reference/list_amazonmanagedstreamingforapachekafka.html, I could not see any actions for kafka-cluster.

How can I use this new feature to authenticate and authorize kafka client using IAM Access Control?
What am I doing wrong here?

Any help would be highly appreciated