How to identify the physical IP of where Kubernetes API server runs
The apiserver runs on master nodes. To get a list of all the master node IP's, this should help-

kubectl -n kube-system get po | grep -i apiserver | cut -f1 -d" " | xargs kubectl -n kube-system get po $1 -o=jsonpath="{.items[*].status.hostIP}"


Based on the version of Kubernetes you are running, you might need to update the location of the hostIP in the jsonPath parameter.