print on both sides of paper

[Douglas McGArrett]

Folks:

System: Kubuntu 22.04

For some unknown reason, the developers don't want the user to print on 
both sides of paper, even if the file is a large one. It would seem that
the printer definition file, which shows both of my printers as "print 
on one side" could fix that IF I could edit the file--but I can't. It 
seems to be
protected by something other than sudo. (Or su -)  Questions: am I 
incorrect that the printer definition file controls this function, and 
if so, how
do I edit the file? (If there is another answer to the 2-sided question, 
please point me to it. The internet answers seem utterly complicated.)

Thank you all--doug