So you don’t have any fire or spark in your ignition system and your lawn mower will not start. That is one of those necessary things to have for your internal combustion engine is a good clean spark.
Without spark or fire, nothing happens and you must have that spark at the right time of day. The ignition system in a lawn mower cycles thousands of times when you use it and it will go bad eventually due to these cycles and the stress of heat. The ignition coil is tucked underneath a cover and it gets pretty hot in there.
You can test your ignition coil by unhooking the black or gray kill wire that is attached to it. But be cautious as you will not be able to shut off the engine with the kill wire unhooked!
If you do get spark, then you know that the ignition coil is good and the problem is in the kill wire system and it is shorting out or a switch is not working properly.
Check all the wiring and switches to find which one is causing the problem and repair it.