On the website for EZVIZ C6T they state that the camera do not support ONVIF and use proprietary protocols for communication with their App. However someone found the correct URL for video and audio. So in NCS add the camera using the tab for Custom URL. Set stream type to rtsp_tcp. For address use:
rtsp://admin:device_verification_code@cameraIP:554/H.264
This give video and audio, but no PTZ.