把下面的代码直接挂载到Text组件上面即可

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
 
public class TextEffects : MonoBehaviour
{
    string str;
    Text tex;
    int i = 0;   //调整这个可以调整出现的速度
    int index = 0;
    string str1="";
    // Start is called before the first frame update
    void Start()
    {
        tex = GetComponent<Text>();
        str = tex.text;
        tex.text = "";
        i = 15;
    }
 
    // Update is called once per frame
    void Update()
    {
        i -= 1;
        if (i <= 0)
        {
            if (index >= str.Length) {
                index = 0;
                str1="";
            }
            str1 = str1 + str[index].ToString();
            tex.text = str1;
            index += 1;
            i = 15;
        }
    }
}

text文字上面挂载这个组件

然后text的锚点按下面设置即可