Arduino for STM32

Hi!
Im trying to program an STM32 Blackpill with the Arduino IDE. When I connect the board the Arduino IDE doesn't detect it (Tools>Port is grayed out), but im still able to upload code in DFU mode. The problem is that then I cannot use the Serial monitor to debug code. Has anyone experience this behavior?

If USB CDC is not enabled in your sketch, you won't see COM port as there isn't one configured.
DFU is completely different thing.

You won't see a COM port if USB CDC is not enabled in your sketch because one has not been set up.