JTable not showing any information. Reading from a text file and adding it to a DefaultTableModel

I am working on a Java Swing project and I am trying to understand how to use JTable.

I have a text file with a list of user information which is all separated by a comma without spaces. I am trying to get this information to be displayed in a table, however, when I run the form the table, it remains blank and never shows anything.

Here is my code:

private JTable listUsersTable;

// ...

String[] columnNames = {"USERNAME", "NAME", "SURNAME", "AGE", "SEX", "SITE"};

// Creates a table with the column names and zero rows.
DefaultTableModel model = new DefaultTableModel(columnNames, 0);

try {
    BufferedReader reader = new BufferedReader(new FileReader("userArchive.txt"));

    // Reads each line in the file "userArchive.txt", separates the data, and puts them into the table.
    String line = reader.readLine();

    while (line != null) {
        String[] lineSplit = line.split(",");
        model.addRow(lineSplit);
        line = reader.readLine(); // Goes to the next line in the file.
    }
    reader.close();

    listUsersTable = new JTable(model);

} catch (FileNotFoundException e5) {
    e5.printStackTrace();
} catch (IOException ex) {
      ex.printStackTrace();
}

And here is my current JTable layout & settings using intelliJ's GUI designer:

Image of my intelliJ GUI designer setup and the JTable in question. (The JTable in the image is called verUsuariosTable however in the code this is called listUsersTable. This is because I am writing my code in Spanish but translating everything to ask the question).

I needed to include JScrollPane to the code. This link shows completely what is needed to work with text files and JTables. (How do I read separate parts from a txt File to show in Java GUI?).

I needed to add

listUsersTable.setPreferredScrollableViewportSize(listUsersTable.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(listUsersTable);

and then add the scrollPane to the panel I was working with using

currentPanel.add(scrollPane);