ArgumentException: Input Axis horizontal is not setup

can someone help me? after putting te code it keeps telling me ArgumentException: Input Axis horizontal is not setup.

here is the code:

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

public class MainMenu : MonoBehaviour
{
public void PlayGame()
{
SceneManager.LoadScene(“Level 0”);
}

public void GoToSettingsMenu()
{
SceneManager.LoadScene(“SettingsMenu”);
}

public void GoToMainMenu()
{
SceneManager.LoadScene(“MainMenu”);
}

public void QuitGame()
{
Application.Quit();
}

}

Firstly -please use the code button in your post so that we can read the code more easily.
Secondly -the cure you have shared has nothing to do with the error message. Please share the code from the correct script. The error message will tell you the exact script and line where the error occurs.
Thirdly-when you find the error, it is most likely that you have written the word "horizontal"wrongly, input axes are case sensitive.