sked/Assets/Script/UI/Loading/UILoading.cs

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

public class UILoading : MonoBehaviour
{
    public float timeLoad = 1f;
    public Slider slider;
    IEnumerator Start()
    {
        float timeSum = 0;
        while ((timeSum += Time.deltaTime) < timeLoad)
        {
            yield return null;
            slider.value = timeSum / timeLoad;
        }

        gameObject.SetActive(false);
    }
}