If the car is out of warranty a garage will charge for investigation, it may be a one off glitch or a faulty component, you could buy a cheap scanner to plug in to find the fault and turn the light off, but there isn’t much you can do yourself to fix the problem unless you have the full computer to reset everything.
Best option is buy an extended warranty
Overwhelmed with detail - i need a minute to digest that one..
under what conditions did it come on?
is there a differnce in anything since it came on?
does not turn off - by itself or with a scanner?
If a scanner which one and what codes did it have?