Hello!
I'm not sure if it's _possible_ to install oVirt on Ubuntu, but it isn't supported:
https://www.ovirt.org/documentation/installing_ovirt_as_a_self-hosted_engine_using_the_command_line/#operating-system-requirements_SHE_cli_deploy
There are older tutorials that claim it works, like https://blog.eldernode.com/install-and-configure-ovirt-on-ubuntu-20-04/
I have not tried that.
What You could do (and which is what I do, although not on Ubuntu) is to run a virtual machine with qemu/KVM and on that VM You'd install CentOS Stream and there You can install and run oVirt. I think that might be easier and/or more reliable (because it's tested better) than getting oVirt to run directly on Ubuntu.
HTH,

rob