stoves with an electrode start igniter do not lite up pilot by adding a flame, that will not work. u need to find out why and where is the power to igniter is not coming from? the spark module or a bad igniter?
The parts diagram here, https://www.appliancepartspros.com/oven-parts-for-whirlpool-ggp84800.html , lists the oven temperature as part 8. That is Whirlpool part AP6011627. Note: the F3 error indicates that the ERC (electronic range control/clock) isn't getting the message from the temperature sensor. It can also occur if the wiring is damaged or the ERC is faulty. You may want to check for damaged wiring if the new sensor doesn't cure the F3 error. Then check the ERC pins where the temperature sensor connects to it.
If the error persists, the only solution is usually to replace the ERC. The ERC for the GGP84800 is not be available any longer as a new part. You may be able to get a remanufactured ERC.
I hope this helps.
Cindy Wells