Question FPS Audio Problem

Hi everyone,
I'm having some trouble with my first person character. I would like to add the footstep sound when the player moves, but I don't know how to connect the public void Sound with the movement.
My Player doesn't have a rigidbody, but just a character controller.
Here's my script

Code (CSharp):

1. public class Player : MonoBehaviour
2. {
3.     public CharacterController controller;
4.     public float speed;
5.     public float gravity;
6.     public float jumpHeight;
7.  
8.     public Transform groundCheck;
9.     public float groundDistance;
10.     public LayerMask groundMask;
11.     Vector3 velocity;
12.     bool isGrounded;
13.  
14.     public AudioSource Footstep;
15.     public AudioClip[] FootstepSound;
16.     void Update()
17.     {
18.         isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);
19.         if (isGrounded && velocity.y < 0)
20.         {
21.             velocity.y = -2f;
22.          
23.         }
24.         velocity.y += gravity * Time.deltaTime;
25.         float x = Input.GetAxis("Horizontal");
26.         float z = Input.GetAxis("Vertical");
27.         Vector3 move = transform.right * x + transform.forward * z;
28.      
29.         controller.Move(move * speed * Time.deltaTime);
30.         //jump
31.         if(Input.GetKeyDown(KeyCode.Space) && isGrounded)
32.         {
33.             velocity.y = Mathf.Sqrt(jumpHeight * -2f * gravity);
34.         }
35.         controller.Move(velocity * Time.deltaTime);
36.         //run
37.         if (Input.GetKeyDown(KeyCode.LeftShift))
38.         {
39.             speed = speed * 2;
40.      
41.         }
42.         else if (Input.GetKeyUp(KeyCode.LeftShift))
43.         {
44.             speed = speed / 2;
45.         }
46.      
47.     }
48.     public void Sound()
49.     {
50.         int random = UnityEngine.Random.Range(0, FootstepSound.Length);
51.         Footstep.PlayOneShot(FootstepSound[random]);
52.     }
53. }

Thanks in advance!