C:\mcDev\mc_code\l5_e1_sol\build_testuart>nrfutil device --x-ext-mem-config-file ./nrf54l15_spi_config.json program --firmware merged.hex --serial-number 69405822
error: unexpected argument '--x-ext-mem-config-file' found

  tip: a similar argument exists: '--x-qspi-config-file'

Usage: nrfutil device <--x-qspi-config-file <PATH>>

For more information, try '--help'.

C:\mcDev\mc_code\l5_e1_sol\build_testuart>