I am afraid to open any thread with "oven" in it, afraid it may have a chicken in it.
First, I would try a second bulb.
Does your oven has a pad you tap, or a switch for the light?
If a pad and the second bulb doesn't work, the sensor on the pad may be bad and for that, you need to replace the pad.
If a switch, you can turn the electricity off and take the switch apart and see what is not working there.