Key broke off in the ignition and will not start

Unfortunately, you will need to remove the key or replace the cylinder. What is happening is the key was allowing the ignition to turn because it was in the correct position to put all the in the coding slugs in the correct location to allow it to turn.

Unfortunately we don't have a service info on this vehicle as Nissan did not give much detail on things like this so I found a video on a similar vehicle. The steps should be about the same but the trim panels are clearly going to be different since this is a Frontier.

https://www.youtube.com/watch?v=FsB9FX8nAMI

Let me know if you have questions and we can go from there. Thanks