did you use that st-link dongle as like discussed?
https://www.adafruit.com/product/2548
https://www.st.com/en/development-tools/st-link-v2.html
stm32f103xx needs to use that st-link dongle or a usb-uart dongle to program it.
if the programming succeeds but that the sketch didn't work, that is a different issue
note that the 'official' stm core is here
https://github.com/stm32duino/Arduino_Core_STM32
and the wiki is here
https://github.com/stm32duino/Arduino_Core_STM32/wiki
there is an 'old' (Libmaple) community core here and the wiki in the repository
https://github.com/rogerclarkmelbourne/Arduino_STM32
there are some other cores / copies of the codes scattered around the internet which are likely forks of these original or that they may be different implementations.
then not least, there are 'clone' stm32f103 'like' chips which may not be made by ST, make sure you are using an original STM32 if you are after all using the original stm32 tools. then for the boards, check the chips, some vendors substitute different chips e.g. stm32f103c6 (only 32k flash) rather than the correct stm32f103c8 (64k flash) or better stm32f103cb (128k flash) chips. and some vendors substitute 'clone' chips on the boards
if you are new to stm32
get one of the Nucleo boards
https://github.com/stm32duino/Arduino_C ... -64-boards
like Nucleo F401RE
https://www.st.com/en/evaluation-tools/ ... 401re.html
Nucleo F401RE
https://www.st.com/en/evaluation-tools/ ... 411re.html
then Adafruit has a board with much faster chip stm32f405
https://www.adafruit.com/product/4382
https://github.com/stm32duino/Arduino_C ... 2f4-boards
which is also used in the micropython board
https://store.micropython.org/product/PYBLITEv1.0
and Olimex has something similar
https://www.olimex.com/Products/ARM/ST/STM32-H405/
there are also other boards e.g. the stm32f401 / f411 'blackpill' type boards. etc. search the online markets for them.
these boards and chips are recommended because they have lots of sram and flash, and stm32f405 is fast, so that you won't need to worry about it mostly while getting started learning the mcu platform. STM32 is a large family of microcontrollers.
if you use the 'official' STM core
https://github.com/stm32duino/Arduino_Core_STM32
it would be much easier to switch between different microcontrollers in the family.
Then for boards, there are many with different stm32 chips and that extends further to 3d printer boards a lot of them use stm32 among the offereings.