Issue with Adding DP-9841 and DP-9851 Phones in Cisco CUCM 15

[sanjinz85]

I'm encountering an issue with adding new phones to Cisco CUCM 15. When I attempt to add the phones by navigating to Device -> Phones and selecting "Add Phones," the devices I want to add, specifically the DP-9841 and DP-9851 models, are not listed. Could you help me identify what might be causing this issue or what I might have overlooked?