Stm32CubeProgrammer is the last most powerful option for DFU and ST-Link firmware update.

https://www.st.com/en/development-tools/stm32cubeprog.html to download

Cube is simple to use, place device in dfu

Search usb, it would see chip connected to usb

Open hex and download

A major down side of Stm32CubeProgrammer is this driver issue.

See also HOWTO-nDBANK