Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wb/STM32WB15_CM4/PWR/CR2#0x0
Power control register 2
Power voltage detector enable
Power voltage detector level selection
Peripheral voltage monitoring 3 enable: VDDA vs. 1.62V
https://github.com/modm-io/cmsis-svd-stm32