I can't find my scriptable object though I've creat asset menu...

I have a script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[CreateAssetMenu(fileName ="HelloWorld",menuName ="testing",order=1)]
public class Testscriptobj : ScriptableObject {

}

I wrote this according to tutorial:

using UnityEngine;

[CreateAssetMenu(fileName = "Data", menuName = "ScriptableObjects/SpawnManagerScriptableObject", order = 1)]
public class SpawnManagerScriptableObject : ScriptableObject
{
    public string prefabName;

    public int numberOfPrefabsToCreate;
    public Vector3[] spawnPoints;
}

but the object “HelloWorld” didn’t appear in my assets menu:
[139659-未命名.png|139659]

I’II very appreciate if anyone solve my stupid problem,thanks a lot!

Look This
Unity Scriptable Object - YouTube

Fix all your compiler errors first. Only after that unity will recompile and the ScriptableObject entries will appear in the asset creation menu.