Text not changing through "if" statement

This is sort of a small question, but how do I get this script to run as the text does not change?

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

public class InvestorMood : MonoBehaviour
{
    public Text investorMoodText;
    public BuyItems buyitemscript;

    public void ChangeText() {
        if(buyitemscript.cash >= 0) {
            investorMoodText.text = "Investor Mood: Very Angry";
            print("test");
        }
    }
}

I’ve referenced the variables, however the issue is still going on. Any help?

Does anyone know how to call this function every frame inside my scene? Sorry if the question is very simple, I am a beginner.

Try to review your code using ChatGPT and verify the tips it will provide.

Update function