How to SSH into GKE node on a private cluster

I have created a private cluster on GKE and a NAT is configued along with the cluster. I also have a bastion setup to access the private cluster.
I’m trying to SSH into one of the nodes and unable to do so since private nodes do not have an external IP.
Is there any way in which I can do this?

Cluster information:

Kubernetes version: 1.13.11-gke.14
Cloud being used: GKE
Host OS: Ubuntu

Have you tried port forwarding from the host? Otherwise I think you would have to expose a ssh on the Ubuntu host that would allow you to ssh to the node.

Can you ssh from the Bastion host into any nodes in the cluster? (Both have private IP’s). If not you should fix that first.