Doesn't work in R23 as described

[jgrean81]

Used this in R21 no problems for a long time.
Mac 10.13.6

Downloaded c4d-pvrenderqueue-2.3.1 and tried in plugins folder in both
/Library/Preferences/MAXON/Maxon\ Cinema\ 4D\ R23_2FE1299C/plugins/c4d-pvrenderqueue-2.3.1
and
/Applications/Maxon\ Cinema\ 4D\ R23/plugins/c4d-pvrenderqueue-2.3.1

but it doesn't show up anywhere, not under "Extensions" or "Scripts" or via commander. Nothing.
No specific details on installation in the readme or other docs.

Where does it go and how do you get it working for R23 please?
Thanks