hello i use this script and when i build the game is give me this error CS0246,Hello I use this scrip could anyone help me its error CS0246

I use this script using UnityEngine; using UnityEditor; public class MakeBirdObject { [MenuItem("Assets/Create/Bird Object")] public static void Create() { Birdobject asset = ScriptableObject.CreateInstance(); AssetDatabase.CreateAsset(asset, "Assets/NewBirdObject.asset"); AssetDatabase.SaveAssets(); EditorUtility.FocusProjectWindow(); Selection.activeObject = asset; } } ,using UnityEngine; using UnityEditor; public class MakeBirdObject { [MenuItem("Assets/Create/Bird Object")] public static void Create() { Birdobject asset = ScriptableObject.CreateInstance(); AssetDatabase.CreateAsset(asset, "Assets/NewBirdObject.asset"); AssetDatabase.SaveAssets(); EditorUtility.FocusProjectWindow(); Selection.activeObject = asset; } }