Running latest LMS server and need plugin to always transcode lots of high bit rate material to 16/44 to use with my Sonic Frontiers Dac.

Github releases page says...
C-3PO is now listed in the 3rd party plugins, just select it , restart when requested and visit the C-3PO settings pages (also per player).

... but I find that is not the case for me. Plugin does not appear.

Can anyone point me to instructions to install on Mac directly?