Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wb/STM32WB15_CM4/PWR/CR5#0x0
Power control register 5
Step Down converter voltage output scaling
Step Down converter supplt startup current selection
BORH configuration selection
Enable Step Down converter SMPS mode enabled
https://github.com/modm-io/cmsis-svd-stm32