Which two methods can be used to add a custom UI panel to a Webex room device? (Choose two.)
A. Import an existing panel configuration file by connecting a USB storage drive to the device.
B. Use xAPI to push a JSON panel configuration to the device.
C. Create a panel using the device UI Extensions Editor (previously In-Room Controls).
D. Restore a device backup file present on a PC that contains a panel configuration.
E. From a T-shell session, use the git command to merge the XML configuration of a panel.
I think B&C.
https://help.webex.com/en-us/n18glho/User-Interface-Extensions-with-Room-and-Desk-Devices-and-Webex-Boards