As described in the epic OSSM-5, istioctl is an integral part of Istio which provides debugging/analyzing/diagnostic features that are helpful for users to understand what is happening in their mesh.

OpenShift Service Mesh should provide and support this tool.

For that purprose, users should download istioctl binary from an official Red Hat repository as mirror.openshift.com

Here is the istioctl onboarding document into ContentGateway