https://psref.lenovo.com/syspool/Sys/PDF/ThinkPad/ThinkPad_L440/ThinkPad_L440_Spec.PDF

PSREF implies that no L440 should have a backlit keyboard. Which makes sense the L series are the cheap models so I’d expect them to not have it. Especially since the *40 was one of the first series to even offer backlit keyboard.

T440 for example says:

Keyboard UltraNav 6-row, spill-resistant, multimedia Fn keys, optional LED backlight