CrowdControl/Assets/Scripts/Dev/Bootstrapper.cs

using DG.Tweening;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

public class Bootstrapper : MonoBehaviour
{
    [SerializeField] private Image loadingSlider;
    [SerializeField] private GameObject loadingBarObj;

    // Called from GoogleSignInManager when login is successful
    public void StartGame()
    {
        Debug.Log("Starting game...");
        loadingBarObj.SetActive(true);
        loadingSlider.DOFillAmount(1f, 2.5f).OnComplete(() =>
        {
            SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
        });
    }
}