How to load next scene when pressed a button while playing in unity - unity3d

Question

This what I tried,
I was watching Brackeys
public void PlayGame()
{
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
};

Answer 1

Your script probably doesn't work if you have 1 scene, or the current scene is at the end of the list in Build Settings.
Also you can use it this way:
//Add scenes in inspector
[SerializeField] private List<Scene> _sceneList;
public void LoadNextScene()
{
int currentScene = SceneManager.GetActiveScene().buildIndex;
if (currentScene < _sceneList.Count)
SceneManager.LoadScene(_sceneList[currentScene + 1].buildIndex);
else
print("Its last scene");
}

Answer 2

You can use SceneManager.LoadScene() method to load the Scene by its name or index in Build Settings.
The SceneManager.GetActiveScene().buildIndex gives you the index number of the current scene and you can add an incremental value to navigate to the next scene.
To do that,
Create a new script named SceneController and methods as follows,
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
public class SceneController : MonoBehaviour
{
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
}
public void LoadMenuScene() {
SceneManager.LoadScene("MenuScene");
}
public void NextScene() {
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
}
public void ReloadScene() {
SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
}
}
Add the script to the Canvas object
Add the method to the button OnClick event in the inspector
NB: You can also use name or index values to load the scene (like LoadMenuScene)
For more: https://docs.unity3d.com/ScriptReference/SceneManagement.SceneManager.LoadScene.html