default or selected kernelversion does not have config value CONFIG_BACKLIGHT_AS3711.
Result is shown for kernelversion 5.9.9

AS3711 Backlight

modulename: as3711_bl.ko
configname: CONFIG_BACKLIGHT_AS3711

Linux Kernel Configuration
└─> Device Drivers
└─> Graphics support
└─> Backlight & LCD device support
└─> AS3711 Backlight

If you have an Austrian Microsystems AS3711 say Y to enable the
backlight driver.

source code: