FactManager.cs

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using TMPro;

public class FactManager : MonoBehaviour
{
    [SerializeField] private Button exitButton;

    [SerializeField] private TextMeshProUGUI textMesh;
    [SerializeField] private Image factImage;

    [SerializeField] private Sprite[] bgSprites;
    [SerializeField] private string[] factTexts;

    private void Start()
    {
        if(SceneManager.GetActiveScene().name == "MainMenu")
        {
            exitButton.onClick.AddListener(() => UIManager.Instance.PopUpAnim(gameObject, Vector3.zero));
        }
        else if(SceneManager.GetActiveScene().name == "FactScene")
        {
            exitButton.onClick.AddListener(() => LoadMainMenu());
        }

        SetUpFact();
    }

    private int GetRandomIndex(int max)
    {
        return Random.Range(0, max);
    }

    private void LoadMainMenu()
    {
        SceneManager.LoadScene("MainMenu");
    }

    public void SetUpFact()
    {
        factImage.sprite = bgSprites[GetRandomIndex(bgSprites.Length)];
        textMesh.text = factTexts[GetRandomIndex(factTexts.Length)];
    }
}