Arduino for STM32

Hi, I have creality 3d printer board V4.2.2 and I want to use it as arduino. Board has STM32F103RET6 and built it Ch340G on PA9 and PA10 pins. When I am trying to burn bootloader with STM32CubeProgramer I get error ".. please verify boot mode configuration" Maybe somebody can help me ?

This is link to V4.2.2 Scematic: https://klipper.discourse.group/uploads ... FPNi87.pdf

for this board get a st-link v2 to program it
https://www.adafruit.com/product/2548
https://www.st.com/en/development-tools/st-link-v2.html
the SWD (ICSP port) is shown in the schematic
you would need to connect to those pins with st-link v2

On the schematic:
there is something else unusual about your board, pin 60 boot0 is apparently pulled up to 3.3v. This is unusual and not normal.
if it is indeed the case, there has to be a jumper or some sort to pull BOOT0 to GND instead.
Otherwise, in this mode, you should be able to program it over the on board ch340.

But that if you cannot put BOOT0 to GND after programming, then it'd "forever" remain in program mode.
BOOT0 should be GND - 0v in normal use.
and you set BOOT0 pull up to 3.3v if you want to program it over uart1 (PA9, PA10) - connected to the ch340

You don't need to flash bootloader for this board. There is no native USB on this board (USB pins are used for IIC EEPROM)
You have USB<->TTL on board (CH340) and you can use built-in serial bootloader. You just need proper BOOT0 and BOOT1 pin setup to enter serial bootloader.