I can't go back to chrome os on my Chromebook 11a G6 EE

Hello, I have an Hp 11a G6 EE Chromebook and I am trying to return it to Chrome OS but using the firmware utility script I get the following error. I appreciate any help in advance.
This comes at the end where the error appears

Manufacturer: Google
Mainboard ID: Grunt
This coreboot image (Google:Grunt) does not appear to
be correct for the detected mainboard (Google:Careena).
Aborting. You can override this with -p internal:boardmismatch=force.
An error occurred restoring the stock firmware. DO NOT REBOOT!

Press [Enter] to return to the main menu.