OpenVAS manager (OMP interface) not available via network?

It seems like the GCE does not expose its OMP interface across the network, i.e. it is not possible to control the openvas-manager via the OMP interface across a network.
Is there a way to enable this?
Is it different on the GSM One?


please see the “Protocols” part of the following product comparison where it is shown that the GCE doesn’t offer the OMP protocol / API: