Bind new value to Efi's data

Hi to everyone, i made a script with help from the Jetcat driver script
EFI_JetCat.lua →

just for testing in order see a value on efi’s data. it is working, but i want to add also efi_exasttemp2, i don’t want to use the “gcs:send_named_float”.
i read in AP_EFI_State.h, line 124 → https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_EFI/AP_EFI_State.h
and i saw that there is such parameter.
So how can i bind a value to that parameter and show it to quick tab? I have to build the firmware? I search a little bit on
AP_EFI_MAV.cpp → https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_EFI/AP_EFI_MAV.cpp, there i have to make a correction?

I already have done some changes to my firmware so i know the steps to build a new firmware.
I have upload my test script, i have an error on line 26 of course!
I wiil appreciate if someone explain to me.
Thank you in advance!

Efi_test.lua (849 Bytes)