ssh error while connecting vm from cloud shell

gcloud compute ssh myofficevm

Did you mean zone [us-west1-b] for instance:

[myofficevm] (Y/n)? n

No zone specified. Using zone [us-west1-a] for instance: [myofficevm].

External IP address was not found; defaulting to using IAP tunneling.

ERROR: (gcloud.compute.start-iap-tunnel) Error while connecting [4033: u’not authorized’].

ssh_exchange_identification: Connection closed by remote host

ERROR: (gcloud.compute.ssh) [/usr/bin/ssh] exited with return code [255].