how to make letters appear one by one in a list

i have a dialogue manager in which i can assign the number of lines of text
but i can’t seem to find out how to make the letters appear one by one because the text is in a list . any ideas how to implement it
here is my code.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class DialogueSystem : MonoBehaviour

{

public static DialogueSystem Instance { get; set; }
public GameObject dialoguePanel;
public string npcName;
public List<string> dialogueLines = new List<string>();
Button continueButton;
Text dialogueText, nameText;
int dialogueIndex;



private void Awake()
{
    dialoguePanel.SetActive(false);
    continueButton = dialoguePanel.transform.Find("Continue").GetComponent<Button>();
    dialogueText = dialoguePanel.transform.Find("Text").GetComponent<Text>();
    nameText = dialoguePanel.transform.Find("Name").GetChild(0).GetComponent<Text>();

    continueButton.onClick.AddListener(delegate { ContinueDialogue(); });
    dialoguePanel.SetActive(false);
    if(Instance != null && Instance != this)
    {
        Destroy(gameObject);
    }
    else
    {
        Instance = this;
    }
}
public void AddNewDialogue(string[] lines, string npcName)
{
    dialogueIndex = 0;
    dialogueLines = new List<string>(lines.Length);
    dialogueLines.AddRange(lines);
  
    this.npcName = npcName;
    Debug.Log(dialogueLines.Count);
    CreateDialogue();
}




public void CreateDialogue()
{
    
    dialogueText.text = dialogueLines[0];
    nameText.text = npcName;
    dialoguePanel.SetActive(true);
}

public void ContinueDialogue()
{
    if(dialogueIndex < dialogueLines.Count-1)
    {
        dialogueIndex++;
        dialogueText.text = dialogueLines[dialogueIndex];
    }
    else
    {
        dialoguePanel.SetActive(false);
    }
}

}

You are going to want a coroutine for this. When you create your dialogue, it populates a list, yes? You then immedistely read the first line after being created but only proceeded to the following lines on user input, correct?

So once it is created, you want to start a coroutine like this that will take your provided line, whether it is the first, second, or so on, and display each character one at a time.

{
    Stop coroutine("BuildDialogue");
    StartCoroutine(BuildDialogue(yourLine));
}

IEnumerator BuildDialogue(string line)
{
    TextComponent.text = string.Empty;
    For(int a = 0; a < line.length; a++)
    {
        Text component.text += line[a];
        yield return new WaitForEndOfFrame();
    }
}