1.Carry the smart key or place it inside the vehicle.
2.Make sure the parking brake is firmly applied
3.Place the shift lever in P (Park). Depress the brake pedal fully. You can also start the engine when the shift lever is in the N (Neutral) position.
4.Press the engine start/stop button while depressing the brake pedal.
5.Do not wait for the engine to warm up while the vehicle remains stationary. Start driving at moderate engine speeds. (Steep accelerating and decelerating should be avoided.)
WARNING - Unintended vehicle movement
Never leave the smart key in the vehicle with children or vehicle occupants who are unfamiliar with the vehicle operation. Pushing the engine start/stop button while the smart key is in the vehicle may result in unintended engine activation and/or unintended vehicle movement.

Do not press the ENGINE START/ STOP button for more than 10 seconds except when the stop lamp fuse is blown.
Kia Stinger (CK) 2018-2023 Owner's Manual: Smart Cruise Control (Stop & Go) System
General safety information and caution General Safety Information and Caution Be careful when driving the vehicle using the smart cruise control system as follows. • The smart cruise control system may be restricted to detect distance to the vehicle ahead due to road and traffic conditions.Kia Stinger (CK) 2018-2023 Owner's Manual: Lane Keeping Assist (LKA) system
The Lane Keeping Assist (LKA) system is designed to detect the lane markers on the road with a front view camera at the front windshield, and assists the driver's steering to help keep the vehicle in the lanes. When the system detects the vehicle straying from its lane, it alerts the driver with a visual and audible warning, while applying a slight countersteering torque, trying to prevent the vehicle from moving out of its lane.