Will not start, security light, how to reset the computer and or ignition?

If you turn the key on do you see the security light come on, then go off? If yes, what happens when you turn the key? Does the engine turn over like it normally does but does not start? Or does it do nothing, or maybe just a loud click or thunk?

This guide can help us fix it:

https://www.2carpros.com/articles/how-to-reset-a-security-system

If it turns over okay but is not starting, I would take a look at the crankshaft position sensor and its wiring. They can fail and not set any codes.