ERR_NGROK_SHIP_POOL_CLUSTER_NOT_FOUND: The pool's Kubernetes cluster no longer exists at PROVIDER - ngrok documentation

What does ERR_NGROK_SHIP_POOL_CLUSTER_NOT_FOUND mean?

ngrok returns ERR_NGROK_SHIP_POOL_CLUSTER_NOT_FOUND with this message:

The pool's Kubernetes cluster no longer exists at <PROVIDER>.

Where can I get more help with ERR_NGROK_SHIP_POOL_CLUSTER_NOT_FOUND?

Email support@ngrok.com and include the error code.