Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wl/STM32WL5x_CM0P/FLASH/PCROP1BER#0x0
Flash PCROP zone B End address register
PCROP1B area end offset
https://github.com/modm-io/cmsis-svd-stm32