Need help identifying this!

[takumi_mt]

Hi Guys,

So my JDM Trueno came with a small keychain-like key (Red with three holes at the top, with some brushed gold colour metal inside, 2 cm in size) that I need to point towards some sensor under my dash in order for me to turn the key at the ignition and start the engine. It's like a safety feature and without it, the engine won't turn and start. You'll know that you can start the engine when you hear a beep.

I am trying to research what this is but can't find anything as I don't know what's it called haha! Can anyone help me identify what this safety feature is?

Thanks guys!