The correct answer is Desktops/1024x600x24.
https://help.webex.com/en-us/article/ttk1teb/Phone-features-and-setup-on-Unified-CM#task-template_503baef9-7e6e-4553-81fc-00e192ec6976
This feature is now available on IMP v14 SU1. One caveat is that the procedure needs to be done during a maintenance window since the text conference manager needs to be stopped. Hope this helps. https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cu...