I can't SSH into the manageiq instance on the Google cloud platform

I download the current stable release (Kasparov-1)
I followed the documentation to install manageiq on the Google cloud platform

n1-standard-4 (4 CPU virtuales, 15 GB de memoria)
SSH key configured on metadata of the instance
default-allow-ssh Entry Apply to all IP Ranges: tcp:22

I can’t access to the instance
ssh -i manageiq manageiq@IP-of-the-instance
Permission denied (publickey,gssapi-keyex,gssapi-with-mic).

Note: I can access all instances GCE of my project through VPN