Type Writer Effect in JTextPane

Question

i'm pretty new to coding (about 5 months) and i've been trying to make a custom terminal for a text based RPG. so far i have the terminal working the way it should but i'm looking for ways to rewrite the code to come up with a typewriter effect. here's the code i have for writing the text onto a JTextPane but the code i'm trying to merge doesn't work all too well since i do feel like i am missing something. i've tried searching for what but couldn't find too many answers.

public void print(String s, boolean trace) {
        print(s, trace, new Color(255,255,255), startFont);
    }

    public void print(String s, boolean trace, Color c, boolean startFont) {
        Style style = console.addStyle("Style", null);
        StyleConstants.setForeground(style, c);
        
        if (trace) {
            Throwable t = new Throwable();
            StackTraceElement[] elements = t.getStackTrace();
            String caller = elements[0].getClassName();
            
            s = caller + " -> " + s;
            
        }
        
        if (startFont) {
            console.setFont(new Font("Bookman Old Style", Font.ITALIC, 87));
        }
        
        try {
            document.insertString(document.getLength(), s, style);
        } catch(Exception ex) {}
        
    }

    public void println(String s, boolean trace) {
        println(s, trace, new Color(255, 255, 255));
    }
    
    public void println(String s, boolean trace, Color c) {
        print(s + "\n", trace, c, startFont);
    }

here's the code that i'm trying to implement: Java typewriter effect

when i do use the "g.drawString" method i ususally get an error saying that "g" is null which makes me think that i am missing something and that "g.drawString" would work but i'm very unsure.

i have some ideas on what i should do like maybe try to make the main string public without anything to it/making it into an array or trying to make a whole new render itself for the JTextPane to get the effect but i've had no luck so far. anyone's got any ideas if it's even possible?