password for cloud images?

what is the password for the "ubuntu" and/or "root" user on the cloud images?

i see this has gone unanswered for a while:
https://discourse.ubuntu.com/t/ubuntu-18-04-ova-cloud-username-password/8933

i am using the bionic ova in this case:
https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64.ova

here is someone using openstack that also needs password:
Default username/password for Ubuntu Cloud image?