I tried to add API key but I get the following error:
Release : 4.1, may be observed on 4.0 as well
Component : PRIVILEGED ACCESS MANAGEMENT
This is an internal user that is expected to have an Api Key associated with it. It is uncommon that this key is missing, but that has been observed in at least one environment.
While the problem persists, the Management Console gets conflicting information about the cluster, including which node has the role of Aggregator. You may need to delete the cluster configuration on the Management Console and define it new after adding the API key.