Sony laptop backlight at Startup

When I boot, the backlight works initially during the boot process, that is until we enter Ubuntu. Then there is no backlight.

I found this script which when I do run in terminal, fixes the issue till I boot again. Then I have to run the script again. It requires my password to run. I was hoping to have it as a startup application, but that doesn't work (probably because p/w is required?)

Here's the script:

echo 1 | sudo tee /sys/devices/platform/sony-laptop/kbd_backlight

How do I make it run at startup?

merci