drivers/soc_flash_nrf/prj.conf

CONFIG_STDOUT_CONSOLE=y
CONFIG_FLASH=y
CONFIG_MPU_ALLOW_FLASH_WRITE=y
CONFIG_SOC_FLASH_NRF_EMULATE_ONE_BYTE_WRITE_ACCESS=y
CONFIG_FCB=y
CONFIG_FLASH_MAP=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_FCB=y