Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Microchip Technology/ATSAME51J19A/SUPC/BKOUT#0x0
Backup Output Control
Enable OUT0
Enable OUT1
Clear OUT0
Clear OUT1
Set OUT0
Set OUT1
RTC Toggle OUT0
RTC Toggle OUT1
https://github.com/cmsis-svd/cmsis-svd-data