It won't let me use it on my character, and says it needs to derive from MonoBehaviour,It won't let me put this script onto my character, it says it needs to derive from MonoBehaviour

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

public class PlayerMobility : MonoBehaviour {

 public float speed;
 void FixedUpdate()
 {
     var MousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
     Quaternion rot = Quaternion.LookRotation(transform.position - Input.mousePosition, Vector3.forward);
     transfrom.rotation = rot;
    
 }

}