if its not showing a code and theres no way to make it flash codes then yes, call komatsu

you can try the pedal dance and see if you can make it enter into mode2 (diagnostic mode)
there are several threads in the forum that discuss on how to enter mode2 using this method. Once in mode2 it should flash your error codes on the MIL light.

but keep in mind, if there is an error in the pedal position sensors you will not be able to obtain access into this mode using the manual method and will need to get a service tool or call komatsu.

So is my only option to call in my local Komatsu dealer?

like most of these systems
if you use the pedal dance method to get into the maintenance mode to use the clear routine and the MIL does not clear then the problem causing that light to come on is still present.
You have to resolve the issue before the light will turn off.