How can I make only one scene landspace? other ones are portrait

I have 5-6 scenes in my project. All of them are portrait. But I want to make landspace for just one scene. I tried this

using UnityEngine;

public class Example : MonoBehaviour {

 void Start()
 {
     Screen.orientation = ScreenOrientation.Landscape;
 }

} But it didnt work. I create a new script and add this code. then I add as a component to main camera and I tried to all other scene component(canvas,uı manager,level manager) to find where should I add this script. But I dont know. Where should this script be added?