USB Camera Jupyter lab not detected

Please try the steps to make sure the camera source is good:
Jetson Nano FAQ

Q: I have a USB camera. How can I launch it on Jetson Nano?

And the latest release is for Jetpack 4.5:
Release Support JetPack 4.5 · NVIDIA-AI-IOT/jetbot · GitHub

Please use Jetpack 4.5 and try the package.