Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
This can be due to many problems. Lack of driver or board not plugged in or another program has control of the USB device. Does it show up in the device manager?