Furnace model gmpn100-4 fan kicks on for about 2 min. but ignition won't glow and furnace won't light then it shuts down and does nothing

If you have a multi tester you could unhook the lead wire that goes to the igniter and test at the start up time to see if there is power going to /or trying to start the igniter/glow-plug, if so, probably the igniner is bad. Most of the time when igniter is bad you will see a grayish-white spot on igniter indicating a broken spot