change text value

i have a 2 UI Text fields, and i am trying to make it add 1 to both UI Text fields each time NextLevel method(level Completed, changes to next scene) called, For example, Text1 is 1 and Text2 is 2 and when NextLevel method called i want to change Text1 to 2 and Text2 to 3. this is my first game i tried my ways to complete this but nothing happening , please help me to complete this

    [SerializeField] private Text Text1;
    [SerializeField] private Text Text2;

public void NextLevel()
    {
        currentStage++;
        LevelCompletedMenu.SetActive(false);
        FindObjectOfType<PlayerController>().ResetBall();
        SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
        Debug.Log("Next level called");

//when this method called level will complete and load next Scene(level)
// whenever this method called i want to change Text1 value from 1 to 2 and Text2 value from 2 to 3 and so on every time level completed, i think i need to use PlayerPrefs to save these values so that data passes through next scene
    }

hi @Humansquirrel you could use this code:-

public Text txt1,txt2;
    int lvl1, lvl2;
    void nextlvl()
    {
        txt1.text = lvl1.ToString();
        txt2.text = lvl2.ToString();
        lvl1++;
        lvl2++;
    }