Menu path: Setup > Sessions > RDP > RDP Global > Mapping > Printers

In this area, you can configure printer mapping.

Enable Client Printer Mapping

☑ The locally connected device printer is made available for your RDP sessions, provided that it was not disabled on the server-side. (default)

The printers must be set up on the Devices > Printer > CUPS > Printers - Configure CUPS Printers in IGEL OS page and must be enabled there for mapping in RDP sessions.
Because the device merely places incoming print jobs in a queue, you need to install the printer on the server.