The Hyundai IONIQ Hybrid uses a foot brake for its parking brake.
The foot brake is in the form of a small lever located to the left of the brake pedal as shown below.
To release the foot brake, use your left leg to step on the small lever beside the brake pedal. It should spring back up when the foot brake is fully released.
When parking your car, remember to engage the foot brake by stepping on the small lever.