The remote start option for the 2018 Kia Optima is triggered from a special key fob. The simple device has one button that controls the door locks and the remote start option. To start the car remotely, push and hold until the lock button is displayed, then press and hold for a couple of seconds and the car will start.
Can I start my Kia with my key fob?
Kia Remote Start via Smart Key and Push Button Here's a list of the impressive capabilities of Kia Remote Start using your Smart Key: Start or stop engine from outside the car. Lock or unlock doors remotely. Immobilize the car so that it can not start without the Smart Key.