Network Printer / Print Server in ERPNext

I was looking for this too. I don’t think this is possible through the UI.
Printing to a network printer/print server seems to be possible via API though. Through the API endpoint /api/method/frappe.utils.print_format.print_by_server.
Three parameters are needed: doctype, name and printer_setting (which is the name given to your network server when adding it to ERPNext).