Epson WorkForce Pro WF-R8590 DTWF - Manual (Page 233)

10. Insert a label showing the size of the paper to be loaded in the cassette into the holder.
11. Insert the paper cassette.
12. Place the sticker indicating the cassette number.
13. Reconnect the power cord and any other cables, and then plug in the printer.
14. Turn on the printer by pressing the P button.
15. Pull out and reinsert the optional paper cassette unit to check that the optional paper cassette unit is displayed
on the Paper Setup screen.
Note:
When uninstalling the optional paper cassette unit, turn off the printer, unplug the power cord, disconnect any cables,
and then perform the installation procedure in reverse.
Proceed with the printer driver settings.
User's Guide
Appendix
233