Now that you've written a beginning to your story, the reader is up to date with backstory, is up to date with your main character and is settled into your story. You have to propel your main character into a conflict.

An inciting incident should occur just as the reader is getting comfy with the story but can have build up to it.

For example: Harry lives an average life until he finds out he is a wizard, but days before the inciting incident(when Hagrid crashes into his house), owls start circling his neighbourhood, letters are delivered to his house and he makes the glass around the snake disappear, this is all leading up to the inciting incident, it isn't as if one day Hagrid shows up and tells Harry he's a wizard, you have to build towards it.

An inciting incident can be defined as an action or situation that propels the main character into the conflict of the story, when creating an inciting incident it must change the flow of the story ie: Katniss would never have entered the hunger games if her younger sister wasn't drawn from the raffle. Darrow would never have become a gold if his wife wasn't sentenced to death. Thomas would never have become a runner if he didn't try to save Alby's life by diving into the maze. These are all examples of "inciting incidents."

An inciting incident can be anything as long as it changes the flow of your story.

This is all on inciting incidents, thank you for reading, the next chapter will be on how to write a description, stay tuned for it.