The spark igniter tip is dirty (can clean it with either a little wire brush or a piece of fine sandpaper).
2) The Pilot flame is too low, and the tip of the igniter is not in the flame good enough. (the flame acts as a circuit when it touches the tip & completes the circuit).
3) The spark module is no good and needs to be replaced.(But 1 & 2 are your best bet).
does not sense the flame when it's on. The spark igniter is also the flame sensor which provides feedback to the spark module.
Make sure the igniter is properly aligned with the burner lighting holes and it is clean. All lighting holes must be clean too. You can enlarge them using a drill bit one size bigger.
If it would not fix the problem, replace the bake burner and the igniter.
There is a small chance for the spark module itself to be bad as well.
The oven safety valve
(also called the gas valve) is the part that ensures that gas is not released until the igniter has reached the correct temperature needed to ignite the gas. While this part can fail, it is uncommon. If the hot surface igniter does not glow you should first verify that you have voltage to the circuit. This is a live voltage check and should be performed by a qualified person. If voltage is lost at the valve terminals then you should verify the continuity of the bi-metal in the valve using a multi-meter.