C# On Click sound to play before loading scene

I have looked at other questions asked but couldn't find anything related with how I set up my menu. I have a script called "UI Click" and add script to button.

[RequireComponent(typeof(Button))] public class UIClick : MonoBehaviour {

 public AudioClip sound;
 private Button button { get { return GetComponent<Button>(); } }
 private AudioSource source { get { return GetComponent<AudioSource>(); } }


 // Use this for initialization
 void Start () {
     gameObject.AddComponent<AudioSource>();
     source.clip = sound;
     source.playOnAwake = false;

     button.onClick.AddListener(() => PlaySound());
 }
 
 // Update is called once per frame
 void Update () {
     
 }

 void PlaySound()
 {
     source.PlayOneShot(sound);
 }

}

Code button is using to load level:

public class ButtonManager : MonoBehaviour { void Start() {

     Cursor.visible = true;
     Cursor.lockState = CursorLockMode.None;
     AudioListener.pause = false;
     //Make sure time is normal when game is starting
     Time.timeScale = 1; //setting time back to normal

 }
 public void LoadScene(string newGameLevel)
 {
     SceneManager.LoadScene(newGameLevel);
 }

}

I am still learning to code so I am not sure what to do to get it to finish playing the whole sound before loading the next level.