How to reset a timer with his fill and text

Question

I got this code of a timer, it is composed of a fill and a text because I don't want to only see numbers decreasing, so it was decided to use a fill to make it more striking. It works correctly but I want the counter to restart when it reaches 0. I want it to be an infinite counter, that when the scenario is running, when it reaches 0 it restarts without having to pause and play it again. Have problems when trying to restart the fill

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

public class Timercountdown : MonoBehaviour
{
    [SerializeField] private Image uifill;
    [SerializeField] private Text uitext;
    public int Duration { get; private set; }

    private int remainingDuration;

    private void Awake()
    {
        ResetTimer() ;
    }
    private void ResetTimer()
    {
        uitext.text = "00:00";
        uifill.fillAmount = 0f;

        Duration = remainingDuration = 0;
    }

    public Timercountdown SetDuration(int seconds)
    {
        Duration = remainingDuration = seconds;

        return this;
    }

    public void Begin()
    {
        StopAllCoroutines();
        StartCoroutine(UpdateTimer());
    }

    private IEnumerator UpdateTimer()
    {
        while(remainingDuration > 0)
        {
            UpdateUI(remainingDuration);
            remainingDuration--;
            yield return new WaitForSeconds(1f);
        }
        End();
    }
    private void UpdateUI(int seconds)
    {
        uitext.text = string.Format("{00:00}:{01:00}", seconds/60 , seconds%60);
        uifill.fillAmount = Mathf.InverseLerp(0, Duration, seconds);   
    }

    public void End()
    {
        ResetTimer();
    }
    private void OnDestroy()
    {
        StopAllCoroutines();
    }

}

To set the time, a small code is used, calling the functions of the previous code.

public class Demo : MonoBehaviour
{
    [SerializeField] Timercountdown timer1;
    // Start is called before the first frame update
    private void Start()
    {
        timer1.SetDuration(30).Begin();
    }

}