One is for normal engine coolant, the other is for the motor systems coolant. You shouldn't need to routinely check coolant, but any dealer or auto parts store (and the manual) or Google will give you the correct coolant. You are correct in that usually a manufacturer uses the same coolant for all their models and that may include Hyundai/Kia. Sorry, I don't know the coolant type. In older cars I've had, I've just added water, not living in a critical environment.
2018 Kia LX HEV Metal Stream with Advanced Tech