Specific problem with error CS0246

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

public class PlayerInteraction : MonoBehaviour
{
    [Header("Raycasting")]
    [SerializeField] float Reach = 3f;
    Interactable currentInteractable;

    [Header("Keys")]
    [SerializeField] KeyCode Interact = KeyCode.E;
    // Start is called once before the first execution of Update after the MonoBehaviour is created
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        CheckInteraction();
        if (Input.GetKeyDown(Interact) && currentInteractable != null)
        {
            currentInteractable.Interact();
        }
        
    }

    void CheckInteraction()
    {
        RaycastHit hit;

        Ray ray = new Ray(Camera.main.transform.position, Camera.main.transform.forward);

        if (Physics.Raycast(ray, out hit, Reach))
        {
            if (hit.collider.tag = "Interactable")
            {
                Interactable newInteractable = hit.collider.GetComponent<Interactable>();

                if (currentInteractable && newInteractable != currentInteractable)
                {
                    currentInteractable.disOutline();
                }

                if (newInteractable.enabled)
                {
                    SetNewCurrentInteractable(newInteractable);
                }
                else
                {
                    DisableCurrentInteractable();
                }
            }
            else
            {
                DisableCurrentInteractable();
            }
        }
        else
        {
            DisableCurrentInteractable();
        }
    }

    void SetNewCurrentInteractable(Interactable newInteractable)
    {
        currentInteractable = newInteractable;
        currentInteractable.Outline();
    }

    void DisableCurrentInteractable()
    {
        if (currentInteractable)
        {
            currentInteractable.disOutline();
            currentInteractable = null;
        }
    }
}

To explain, I have been using a tutorial to be able to make an interaction system. Problem is, I keep seeing them use a variable called “Interactable”, but Unity wont seem to identify this variable. I might just be really dumb, but I can’t fix this by myself. I might need to watch a more in depht tutorial that actually explains everything. And I’m pretty sure this isn’t even the best way to do it. I would still like to know why this doesnt work to help me improve my coding skills. Thank you!

Tutorial: https://youtu.be/b7Yf6BFx6js?si=tneBNUn5U8iYwSyx