Make sure you actually have gas to the furnace. Any smell of gas? If you’re getting voltage to the gas valve- it may be stuck. Put your hand on the gas valve and see if you can feel it open up after the inducer/pressure switch proves/hot surface igniter go. I recently had a intermittent issue with a pressure switch that let me to replacing the gas valve before I realized it was the pressure switch intermittently opening/closing
Giving the gas valve a few thwacks with a screwdriver handle could unstick the valve, if that’s the case.
