class wont show up in inspector

Ok, so i’ve made this class called TextSetup, but it wont show up in the inspector when i try to use it. I don’t have a lot of experience using classes so I might have done something wrong, but it would be super neat if I got this to work. :),ok, so i have made this class called TextSetup and it contains three different string. The problem si that when I try to use SerializeField on it, it wont show up in the inspector. I don’t have a lot of experince using classes so i might have done something wrong, but it would be super neat if i got this to work.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;

public class TextSetup
{
    public string text1;
    public string text2;
    public string text3;
}
public class Text : MonoBehaviour
{
  
    [SerializeField]
    TextMeshProUGUI text1;
    [SerializeField]
    TextMeshProUGUI text2;
    [SerializeField]
    TextMeshProUGUI text3;

    [SerializeField]
    TextSetup speach;

    // Start is called before the first frame update
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        text1.text = speach.text1;
        text2.text = speach.text2;
        text3.text = speach.text3;
    }
}

You have to add [System.Serializable] attribute to your TextSetup class