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.
You can change the firmware download directory (which is $HOME/.ac6/SW4STM32/firmwares by default).
Go to Window > Preferences > System Workbench then select your directory.