Availability of macro plugin for older version of Kate

[René J.V. Bertin]

>[My OS is Debian 9.13 and updating *THIS* machine is not practical.]

When did that get out of support, and do you refer to updating via official packages or by building from source yourself?

I've kept my main linux beater on KUbuntu 14.0.5LTS or whatever the official latest version is, but I've used PPAs to update a bunch of packages and use a build/package system based on MacPorts to install a lot of stuff the same way I install it on Mac. I stopped updating my KF5 packages a while back, am now at Kate 19.08.3, could undoubtedly go newer if I wanted.
Anyway, I'm not seeing the plugin you mention either. So either it's part of a newer Kate release, or it's an external plugin. In the former case you might be able to backport it.