How to deactivate a UI button temporarily

I’m making a game where you are trying to get a high score. The first time you die, you have an option to watch an ad and then restart the game with the score that you died with. But I don’t want people spamming this button and getting endless scores so I want to be able to deactivate it once someone has used it once. I have this script below to control a lot of things but the parts I need help with are the very last function and the if statement in the update function. Thanks.

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using UnityEngine.UI;

using TMPro;

using UnityEngine.Advertisements;

using UnityEngine.SceneManagement;

public class ScoreCounter : MonoBehaviour
{

public float score;
public float continueButton;
public Button advertisingButton;
public TextMeshProUGUI scoreText;
public TextMeshProUGUI highScoreText;
public float highScore;
public TextMeshProUGUI isHighScore;
string gameId = "3885078";
bool testMode = true;

private void Awake()
{
    if (PlayerPrefs.HasKey("HighScore"))
    {
        highScore = PlayerPrefs.GetFloat("HighScore");
        highScoreText.text = highScore.ToString();
    }

    if (PlayerPrefs.HasKey("Score"))
    {
        score = PlayerPrefs.GetFloat("Score");
        PlayerPrefs.DeleteKey("Score");
    }
}

void Start()
{
    continueButton = 0f;
    StartCoroutine("Repeater");
    Advertisement.Initialize(gameId, testMode);
}

void Update()
{
    scoreText.text = score.ToString();
    highScoreText.text = highScore.ToString();
    HighScore();

    if (continueButton == 1f)
    {
        advertisingButton.gameObject.SetActive(false);
        continueButton = 0f; 
    }
}
IEnumerator Repeater()
{
    yield return new WaitForSeconds(1.2f);
    InvokeRepeating("Counter", .32f, .32f);
}

void Counter()
{
    score += 1f;
}

void HighScore()
{
    if (score > highScore)
    {
        highScore = score;
        PlayerPrefs.SetFloat("HighScore", highScore);
        isHighScore.SetText("New High Score!");
    }

    if (score < highScore)
    {
        isHighScore.SetText("Current High Score");
    }
}

public void Continue()
{

    if (Advertisement.IsReady("rewardedVideo"))
    {
        Advertisement.Show("rewardedVideo");
        Time.timeScale = 1;
        PlayerPrefs.SetFloat("Score", score);
        SceneManager.LoadScene("Game");
    }
}

public void ContinueButton()
{
    continueButton += 1f;
}

}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using TMPro;
using UnityEngine.Advertisements;
using UnityEngine.SceneManagement;

public class ScoreCounter : MonoBehaviour
{    
    public float score;
    public Button advertisingButton;
    public TextMeshProUGUI scoreText;
    public TextMeshProUGUI highScoreText;
    public float highScore;
    public TextMeshProUGUI isHighScore;
    string gameId = "3885078";
    bool testMode = true;

    private void Awake()
    {
        if (PlayerPrefs.HasKey("HighScore"))
        {
            highScore = PlayerPrefs.GetFloat("HighScore");
            highScoreText.text = highScore.ToString();
        }

        if (PlayerPrefs.HasKey("Score"))
        {
            advertisingButton.gameObject.SetActive(false); // Continue button has been used, disable it
            score = PlayerPrefs.GetFloat("Score");
            PlayerPrefs.DeleteKey("Score");
        }
    }

    void Start()
    {
        StartCoroutine("Repeater");
        Advertisement.Initialize(gameId, testMode);
    }

    void Update()
    {
        scoreText.text = score.ToString();
        highScoreText.text = highScore.ToString();
        HighScore();
    }
    IEnumerator Repeater()
    {
        yield return new WaitForSeconds(1.2f);
        InvokeRepeating("Counter", .32f, .32f);
    }

    void Counter()
    {
        score += 1f;
    }

    void HighScore()
    {
        if (score > highScore)
        {
            highScore = score;
            PlayerPrefs.SetFloat("HighScore", highScore);
            isHighScore.SetText("New High Score!");
        }

        if (score < highScore)
        {
            isHighScore.SetText("Current High Score");
        }
    }

    public void Continue()
    {

        if (Advertisement.IsReady("rewardedVideo"))
        {
            Advertisement.Show("rewardedVideo");
            Time.timeScale = 1;
            PlayerPrefs.SetFloat("Score", score);
            SceneManager.LoadScene("Game");
        }
    }
}