I have not been using unity to program for very long so forgive me if this is a simple fix. I need to get the value of a method and display it in a prefabs text box.

Right not the code reads

public class Turret : MonoBehaviour
{

    public static Turret main;

    [SerializeField] private int baseUpgCost = 75;


    public int GetNewUpgCost()
    {
        return Mathf.RoundToInt(baseUpgCost * Mathf.Pow(level, 2f));
    }

}

In the script with the method and

public class UpgradeUIScript : MonoBehaviour
{

    [SerializeField] TextMeshProUGUI cost;


    private void OnGUI()
    {
        cost.text = "Cost: " + Turret.main.GetNewUpgCost().ToString();
    }
}

in the prefab where I am trying to update the text.

However to code returns “NullReferenceException: Object reference not set to an instance of an object
UpgradeUIScript.OnGUI () (at Assets/UpgradeUIScript.cs:29)
UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr, Boolean&)”

Thanks for any help, again sorry if this is a simple fix I’m very new to programing but I haven’t any similar questions online with answers.