Welcome to LQ!
If you have already installed the printer using CUPS, I would try:
1. Stopping the CUPS daemon.
2. Edit the CUPS printers.conf file and add the NetID to the device URI for your printer
Code:
DeviceURI lpd://<NetID>@ep-ps-campus-01.oit.duke.edu/ePrint-OIT
The syntax is connectiontype://username:password@server/printer
3. Restart the CUPS daemon