Epson Artisan 810 Duplexer support

I am using an Epson Artisan 810 with duplexer installed as one of printers on my network (yeah, I know it's old but it does a fine job). However, I cannot make my software enable duplex printing to it. The duplex options on Preview, for example, are greyed out. I cannot find anything in the basic printer settings to enable it. When I open the Epson printer utility through my iMac settings, it does show the duplexer is installed. I'm running Catalina with the latest printer/scanner drivers. I also run Parallels and although the windows drivers do not have duplexing greyed out, printing duplex has no effect on printed output (all simplex). Any thoughts on how to enable this?