Flashing NX Xavier


I am using the script flash.sh to flash the NX Xavier. I have been using it to flash the SD card, which seems to work properly.

What I want to do now is eliminate the SD card and flash the onboard eMMC and be able to boot from the eMMC after having removed the SD card.

When I remove the SD card and run the command:
sudo ./flash.sh jetson-xavier-nx-devkit internal
sudo ./flash.sh jetson-xavier-nx-devkit mmcblk0p1

The script stops with the following error:

Failed to open instance 0 of device 6

The script seems to want the SD card inserted.

Can you provide the steps to program and boot from the eMMC using the flash.sh script and boot without the SD card?