Try these steps:
1.Check the video feed
Make sure the camera is powered on. If there’s no image, press and hold the reset button for 15 seconds to restore factory settings.
The location of the reset button is roughly shown in the image below：
2.Verify network connection
Download Dahua’s Camera Search Tool on your computer:
https://support.dahuasecurity.com/en/toolsDownloadDetails?IsDpValue=Q93jdSLr94chjRuQ1y%2FcQQ%3D%3D
Run the tool to see if the camera’s IP address appears. If it does, the camera is powered on and connected to the network.
3.Next steps
If the IR light still doesn’t work after these checks, contact support with your order details for warranty service.