Eabyrd1977

so my check engine light does not work... I’ve never had to deal this issue. It’s always stayed on,but never not come on. I swapped the bulbs with ones I know work and still no light. There are a couple bulbs missing and was wondering if I need all the bulbs to complete the circuit maybe? Any info would be great fully appreciated. It’s a 1995 XJ and I need it to cycle the key to check the flashes to see if there’s any codes cause my fuel mileage dropped considerably.