OnMouseDown receiving error [Resolved]

I am receiving for following error with my code:

NullReferenceException: Object reference not set to an instance of an object
Node.OnMouseDown () (at Assets/Scripts/Node.cs:26)
UnityEngine.SendMouseEvents: DoSendMouseEvents(Int32) (at /Users/builduser/buildslave/unity/build/Modules/InputLegacy/MouseEvents.cs:161)

Can someone help? I’m following a tutorial from Brackey’s on YouTube and from what I can tell I have the script exactly the same. However the tutorial is an older tutorial so not sure if something has changed on how it should be written. Below is the coding. Please let me know if you need more information.

If I’m reading everything correctly it’s saying there is an issue here:
GameObject turretToBuild = BuildManager.instance.GetTurretToBuild();

That refers to here:
public GameObject GetTurretToBuild()

That is trying to get this:
turretToBuild = standardTurretPrefab;

I do have the turret named standardTurret and attached to the BuildManager script for the standard turret prefab

Node script:

using UnityEngine;

public class Node : MonoBehaviour
{
    public Color hoverColor;
   
    private GameObject turret;
   
    private Renderer rend;
    private Color startColor;
       
    void Start()
    {
        rend = GetComponent<Renderer>();
        startColor = rend.material.color;
    }
   
    void OnMouseDown ()
    {
        if (turret != null)
        {
            Debug.Log ("Can not build here");
            return;
        }
              
        GameObject turretToBuild = BuildManager.instance.GetTurretToBuild();
        turret = (GameObject)Instantiate(turretToBuild, transform.position, transform.rotation);
       
    }
   
    void OnMouseEnter ()
    {
        rend.material.color = hoverColor;
    }
   
    void OnMouseExit ()
    {
        rend.material.color = startColor;
    }
   
}

BuildManager script:

using UnityEngine;

public class BuildManager : MonoBehaviour
{
   
    public static BuildManager instance;
   
    void awake ()
    {
       
        if(instance != null)
        {
            Debug.Log ("More than one Build Manager in scene");
            return;
        }
        instance = this;
    }
   
    public GameObject standardTurretPrefab;
   
    void Start ()
    {
        turretToBuild = standardTurretPrefab;
    }
   
    private GameObject turretToBuild;
   
    public GameObject GetTurretToBuild()
    {
        return turretToBuild;
    }
}

awake
should be
Awake

That was it!! I must have overlooked that at least a dozen times. Thank you!