virError on Ubuntu 20.04

[leonicode]

Hi to all,
I'm trying to install OKD in my Ubuntu 20.04 but after I started with the following command:

./openshift-install create cluster

the system terminates with the error message:

---

ERROR Error: virError(Code=38, Domain=7, Message='unable to connect to server at '192.168.122.1:16509': Connection refused')
ERROR
ERROR on ../../tmp/openshift-install-998134580/main.tf line 1, in provider "libvirt":
ERROR 1: provider "libvirt" {
ERROR
ERROR
ERROR Failed to read tfstate: open /tmp/openshift-install-998134580/terraform.tfstate: no such file or directory
FATAL failed to fetch Cluster: failed to generate asset "Cluster": failed to create cluster: failed to apply Terraform: failed to complete the change

Virtlib is present and correctly running because the command "sudo systemctl is-active libvirtd" says "active"; it seems
that libvirtd isn't listening @PORT 16509 ... is it possible ?
Need I to install some other packages ?

Thanks in advance
Leonard