Unable to write to sys folder

To install the lte modem drivers, I have to go through this folder. But I am getting the error in the picture.!
mkdir: ‘/sys/kernel/example’: Operation not permitted

android 9 latest version
khadas vim 3 pro
the device is turned on and connected to the pc with adb.
I was able to do many writes in the other folder. But although I have tracks in the sys folder, I cannot write. root privileges have been acquired.

You can’t write to the kernel.
You will have to integrate the files into the kernel source code and rebuild the kernel and flash it.

How will I integrate it into the img file. I tried the img file with many programs but I cannot open it.