https://medium.com/@pudding_entertainment

6.cs

public class ChangeOrientationButton : MonoBehaviour
{
   public void ChangeOrientation()
   {
       if (Screen.orientation == ScreenOrientation.Portrait)
       {
           Screen.orientation = ScreenOrientation.Landscape;
       }
       else
       {
           Screen.orientation = ScreenOrientation.Portrait;
       }
   }
}