Type or name space cannot be found

Hi I'm following a Brackeys tutorial and it says that my PlayerMotor is not found.

Here is the code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 [RequireComponent(typeof(PlayerMotor))]
 public class PlayerController : MonoBehaviour {
 
     public LayerMask movementMask;
 
     Camera cam;
 
     PlayerMotor motor;
 
     // Use this for initialization
     void Start () {
         cam = Camera.main;
         motor = GetComponent<PlayerMotor>();
     }
     
     // Update is called once per frame
     void Update () {
         if (Input.GetMouseButtonDown(0))
         {
             Ray ray = cam.ScreenPointToRay(Input.mousePosition);
             RaycastHit hit;
                 if (Physics.Raycast(ray, out hit, 100, movementMask))
             {
                 Debug.Log("We hit" + hit.collider.name + " " + hit.point);
             }
         }
     }
 }
 

Then here is my PlayerMotor code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.AI;
 
 [RequireComponent(typeof(NavMeshAgent))]
 public class PlayerMotor : MonoBehaviour {
 
     NavMeshAgent agent;
 
     void Start () {
         agent = GetComponent<NavMeshAgent>();
     }
     
     // Update is called once per frame
     public void MoveToPoint (Vector3 point)
     {
         agent.SetDestination(point);
     }
 }