Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32c0/STM32C071/PWR/PWR_BKP1R#0x0
PWR backup 1 register
Backup bitfield This bitfield retains information when the device is in Standby.
https://github.com/modm-io/cmsis-svd-stm32