sudo snap install lxd

or

sudo apt-get install lxc

lxc info

returns:

If this is your first time running LXD on this machine, you should also run: lxd init
To start your first instance, try: lxc launch ubuntu:18.04

Unprivileged containers are the safest containers.

Those use a map of uid and gid to allocate a range of uids and gids to a container.

That means that uid 0 (root) in the container is actually something like uid 100000 outside the container.

So should something go very wrong and an attacker manages to escape the container, they'll find themselves with about as many rights as a nobody user.