Is it possible to get the keypair from GKE?
This SO post makes it seem impossible, but maybe there is a workaround: https://stackoverflow.com/questions/53182206/get-a-kubectl-client-key-and-cert-when-using-gke
StackOverflow is a great resource, but remember that the posts are not authoritative. if in doubt double check in the vendor documentation.
Can you clarify what keypair you are referring to, and what platform you are running on.
Are you not able to use the process described in the demo ?