Unable to see custom object in Inspector.

Hello,

I'm following this tutorial: https://www.youtube.com/watch?v=xenW67bXTgM&t=639s and I'm at the point when he makes the bullet shoot in the direction of his gun (around 18th minute). My problem is that I can't make the public field for his RotateToMouse class show in the SpawnProjectile script. I've tried using Serialized fields but didn't or I didn't use them properly. Resetting scripts after editing also didn't help, and I don't know where could be the issue.
Here is my BulletToMouse script:

  using System.Collections;
     using System.Collections.Generic;
     using UnityEngine;
     
     public class BulletToMouse : MonoBehaviour
     {
         public Camera dashCam;
         public float maxLength;
         private Ray rayMouse;
         private Vector3 pos;
         private Vector3 direction;
         private Quaternion rotation;
     
         // Update is called once per frame
         void Update()
         {
             if(dashCam != null){
                 RaycastHit hit;
                 var mousePos = Input.mousePosition;
                 rayMouse = dashCam.ScreenPointToRay(mousePos);
                 if(Physics.Raycast(rayMouse.origin,rayMouse.direction,out hit, maxLength)){
                     RotateMouseDirection(gameObject, hit.point);
                 } else {
                     var pos = rayMouse.GetPoint(maxLength);
                     RotateMouseDirection(gameObject, pos);
                 }
                 
             }
         }
         void RotateMouseDirection(GameObject obj, Vector3 destination){
             direction = destination - obj.transform.position;
             rotation = Quaternion.LookRotation(direction);
             obj.transform.localRotation = Quaternion.Lerp(obj.transform.rotation, rotation, 1);
     
         }
     
         public Quaternion GetRotation(){
             return rotation;
         }
     }

And BullerSpawn script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class SpawnBullet : MonoBehaviour
 {
     public BulletToMouse bulletToMouse;
     
     public GameObject firePoint;
     public GameObject gun;
     public GameObject[] vfx;
     private GameObject effectToSpawn;
     void Start()
     {
         effectToSpawn = vfx[0];
     }
 
     // Update is called once per frame
     void Update()
     {
         if(Input.GetMouseButton(0)){
             SpawnVFX();
         }
     }
 
     void SpawnVFX()
     {
         GameObject vfx;
         if(firePoint != null){
             vfx = Instantiate(effectToSpawn, firePoint.transform.position, firePoint.transform.rotation);
             if( bulletToMouse != null){
                 vfx.transform.localRotation = bulletToMouse.GetRotation();
             }
         }
     }
 }

Thanks in advance.