Usually F3 boards will come with Cleanflight 1.9.0 and there has been a tonne of updates since then.
I tried flashing and kept getting the error “Communication with bootloader failed”
Download the latest Betaflight or Cleanflight from the website (at this time it is betaflight_2.6.1_SPRACINGF3.hex)
Then goto firmware on clean flight configuration tab and make sure you load the file then change the settings to this
-Full chip erase.
-Manual baud rate 256000.
Flash and it should work!