I can't write on the registers of m MCU (nucleo-g071RB board). I am a total beginner and I have tried to configure ADC on m MCU. For this purpose I have tried to configure RCC for the APB bus which control ADC. But it doesn't work at all.

[Tesla DeLorean]

Perhaps try mastering simpler stuff first?

Look at the HAL based examples, and source for the library, get an understanding of how this works, and the reference manual description of the registers, then apply that to a register level usage.

[S.Ma]

Sometime progressing learning is better than cliffhanging. Check out if there are STM32 arduino support.

[gbm]

And what exactly doesn't work? You didn't show even a single line of your code, so what kind of help you expect? Use the debugger, use the ADC register view in SFR (close it after you get the conversion working, since it will interfere with your code when you reach that point); you should be able to see the problem.

[Pavel A.]

Here beginners can find help for their projects.