I thought, why not try to send the printed PNG to the printer:

dofile('../../luaprinter2.lua') -- start up my imagewriter interpreter

(print something to the page)

os.execute('lpr ~/"Downloads/mamegit/mame/snap/ct486/2020-09-18 08-59-47 ct486-board4-lpt-lpt-centronics-luaprinter Page 0.PNG"')

and lpr sends the PNG file to the printer.

Ubuntu uses cups, I don't know how it would work on windows.