How to change the video capture device resolution in Visionworks?

Please follow the steps in
Jetson Nano FAQ
Q: I have a USB camera. How can I launch it on Jetson Nano?

And check if 720x480 is supported, and you can launch it in gst-launch-1.0 command.

Beside, we would suggest use VPI rather than VisioWorks. Please check:
VPI - Vision Programming Interface: Installation

Most functions in VisioWorks are supported in VPI. Please take a look at the document: