Hmm ... interesting ... yes, right-click -> Export -> Helicon Fucos (DNG) is present, enabled, and functions as expected (as does the TIFF alternative).
So ... the plug-in is useable, if not in the way to which I'm accustomed ...
Quite odd ...

As for Plugin Manager: it shows
"Helicon Focus Explore ...

I am setting up a new machine to replace one that failed.
I have installed Lightroom Classic (14.1.1 release) and restored all preferences, presets, templates, etc. All seemed well.
I installed Helicon Focus 8.3.0 Pro

In LrC I select two .cr3 files,
then File > Export ...
and the two presets for ...