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 start a debug session or the simply click on "run". This will automatically flash the board.
either from the icons (use the mouse a pop up will show what each button means) or under the menu "Run"