Huh? It's right there in the docs: https://podman.io/docs/installation#installing-on-linux

    apt-get -y install podman

Podman doesn't produce their own binary distributions for ANY Linux distro. The only binary packages they provide are for Mac and Windows because those don't have a native package repository.

Even if they did release their own Linux packages, bear in mind that Podman development is driven by and sponsored almost entirely by Red Hat. It's not really in their interest to pay their developers to maintain packages for Ubuntu, a direct competitor in the enterprise Linux space.