[cups] Printing 2 copies on a double sided printer

[Axel Braun]

Hallo Helge,

Am Samstag, 3. Oktober 2020, 18:33:45 CEST schrieb Helge Blischke:
> The best method to solve this issue once for all is to set
> default-collate=true
> by lpadmin for the printer in concern.
> Then cups marks the Collate option in the printer’s PPD if present
> or sets the internal attribute slow_collate, which means the whole
> job is repeated times the number of copies.

X1E:/home/docb # lpadmin -p MFC9340CDW -o default-collate=true

X1E:/home/docb # more /etc/cups/ppd/MFC9340CDW.ppd | grep collate
X1E:/home/docb # 

(no output)
Was the syntax of the command wrong or do I need to set something manually in 
the ppd file?

Thanks
Axel