Jetson AGX flash devicetree fail

I’m making a customer board for Jetson AGX.So,I’m trying to change the devicetree with '$ sudu ./ -r -k kernel.dtb jetson-agx mmcblk0p1 ',but it doesn’t work , return ’ command not found '.

  1. Should i need to flash on ubuntu computer?
  2. If I succeed in flashing, Do I just need restartting my AGX?