script class cannot be found error (v.2022.1)

I am new to Unity and I have this C# script with the title "LookAtTarget". It appears the script and class names match, so I do not know what is happening because when I try and add the script to an object in my game I receive this error message:

Here is my script using System; using UnityEngine;

 public class LookAtTarget : MonoBehaviour
 {
      public Transform target;
 
 
   void Update()
   {
        if(target != null)
        {
             transform.LookAt(target);
        }
   }
 }