E: Package 'openresolv' has no installation candidate (Ubuntu 22.10)

So this is a pretty obvious error but I can't understand why.

I have run

sudo apt update

and then try to install using

sudo apt -y install openresolv

Which gives the error

Package openresolv is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'openresolv' has no installation candidate

I need this package to run the PureVPN client.

Since Ubuntu Kinetic 22.10, the default implementation and I believe only implementation of resolv.conf and as such, both the resolvconf and openresolv implementations of resolvconf functionality were removed during the 22.10 development cycle.

Per removal bug #1990743 on Launchpad:

systemd-resolved now implements the resolvconf interface, and Conflicts: with other implementations of resolvconf. Installing these other implementations on a full system or container will wrongly result in removal of the systemd-resolved package. We should drop resolvconf and openresolv now from the archive (and blacklist them). -- bug description

Upon further inspection, it turns out that systemd-resolved now implements the resolvconf interface. We should drop resolvconf and openresolv now from the archive, and users requesting resolvconf will be directed to systemd-resolved. Packages which depend/recommend systemd-resolved will also get the supported implementation going forward.

Using this bug for the removal of resolvconf and openresolv.

--comments by Steve Langasek (vorlon), an archive admin and seasoned Ubuntu developer

If openresolv is required by PureVPN, you will need to talk to the PureVPN developers and have them provide updated packages because systemd-resolved is now the primary mechanism for resolvconf interfaces. PureVPN developers will need to update their packaging in accordance with this change and removal.