What you're looking at is the OpenStack client version:

root@ops:~# openstack --version

If you want to know the versions of the various OpenStack components, you need to be looking at the versions of packages like Nova, Keystone, etc, and comparing with https://releases.openstack.org/ussuri/index.html.

On Mon, 21 Sep 2020 at 08:39, <ops@clustspace.com> wrote:
Hello,

We are decided to change Apache CloudStack to OpenStack.

Trying to install, but only Stein....As you can see we have repositories
ussuri

root@ops:~# apt update
Hit:1 http://ubuntu-cloud.archive.canonical.com/ubuntu
bionic-updates/ussuri InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu bionic InRelease
Hit:3 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
root@ops:~#


But after installation we got only Stein

root@ops:~# openstack --version
openstack 5.2.0


Do'es anyone have idea why we can install only Stein?