Unable to check input action

I migrate my old player controller to the new input system, but I don't know how to check if my player moves and run the walking animation. If someone shows me a way to do it, I appreciate it. The Script Player:

 public class PlayerMovement : MonoBehaviour
 {
     Rigidbody2D rb;
     public Transform groundCheck;
     public Transform groundCheckL;
     public Transform groundCheckR;
     public LayerMask groundLayer;
 
     private float horizontal;
     private float speed = 2.5f;
     private float jumpingPower = 6f;
     private bool isFacingRight = true;
     public bool isGrounded;
     private bool isShooting;
     private bool isAttackPressed;
     private bool isAttacking;
     bool isFacingLeft;
 
     bool crouch = false;
 
     Animator animator;
     private string currentState;
 
     public bool isWalking = false;
 
     //Animation States
     const string PLAYER_IDLE = "Player_idleV2";
     const string PLAYER_WALK = "Player_walkV2";
     const string PLAYER_JUMP = "Player_jump";
     const string PLAYER_DOUBLE_JUMP = "Player_doublejump";
     const string PLAYER_ATTACK = "Player_throwV2";
     const string PLAYER_MOVE_ATTACK = "Player_walk_throw";
     const string PLAYER_CROUCH = "Player_crouchV2";
 
     AudioSource audioSource;
     public AudioClip ThrowClip;
     public AudioClip JumpClip;
     public AudioClip CoinClip;
     public AudioClip DamageClip;
     public AudioClip PickUpClip;
 
     [SerializeField]
     private float shootDelay = .5f;
 
     [SerializeField]
     private float attackDelay = .5f;
 
     [SerializeField] private GameObject bulletPrefab;
 
     [SerializeField] private Transform bulletSpawnPos;
 
     public GameObject ColliderPlayer;
     public GameObject ColliderCrouch;
 
     void Start()
     {
         rb = GetComponent<Rigidbody2D>();
         animator = GetComponent<Animator>();
         audioSource = GetComponent<AudioSource>();
     }
 
     void ChangeAnimationState(string newState)
     {
         //stop the same animation from interrupting itself
         if (currentState == newState) return;
 
         //play the animation
         animator.Play(newState);
 
         //reassign the current state
         currentState = newState;
     }
 
     // Update is called once per frame
     void Update()
     {
         if (Physics2D.Raycast(groundCheck.position, Vector2.down, 0.25f, groundLayer) || Physics2D.Raycast(groundCheckL.position, Vector2.down, 0.25f, groundLayer) || Physics2D.Raycast(groundCheckR.position, Vector2.down, 0.25f, groundLayer))
         {
             isGrounded = true;
         }
         else
         {
             isGrounded = false;
         }
 
         rb.velocity = new Vector2(horizontal * speed, rb.velocity.y);
 
         if (!isFacingRight && horizontal > 0f)
         {
             Flip();
             isFacingLeft = false;
             
             //if (isGrounded && !isAttacking)
         }
         else if (isFacingRight && horizontal < 0f)
         {
             Flip();
             isFacingLeft = true;
             
             //if (isGrounded && !isAttacking)
         }
         else
         {
             if (isGrounded && !isAttacking)
             {
                 isWalking = false;
                 if (isWalking == false)
                 {
                     ChangeAnimationState(PLAYER_IDLE);
                 }
                 else
                 {
                     ChangeAnimationState(PLAYER_WALK);
                 }
             }
 
         }
 
         if (isAttackPressed)
         {
             isAttackPressed = false;
 
             if (!isAttacking)
             {
                 isAttacking = true;
 
                 if (isGrounded && !isWalking)
                 {
                     ChangeAnimationState(PLAYER_ATTACK);
                 }
                 else if (isGrounded && isWalking)
                 {
                     ChangeAnimationState(PLAYER_MOVE_ATTACK);
                 }
 
                 Invoke("AttackComplete", attackDelay);
 
             }
         }
     }
 
     private bool IsGrounded()
     {
         return Physics2D.Raycast(groundCheck.position, Vector2.down, 0.25f, groundLayer) || Physics2D.Raycast(groundCheckL.position, Vector2.down, 0.25f, groundLayer) || Physics2D.Raycast(groundCheckR.position, Vector2.down, 0.25f, groundLayer);
     }
 
     private void Flip()
     {
         isFacingRight = !isFacingRight;
         Vector3 localScale = transform.localScale;
         localScale.x *= -1f;
         transform.localScale = localScale;
     }
 
     void AttackComplete()
     {
         isAttacking = false;
     }
 
     public void Move(InputAction.CallbackContext context)
     {
         horizontal = context.ReadValue<Vector2>().x;
         if (context.performed)
         {
             //button is press
             isWalking = true;
         }
         else if (context.canceled)
         {
             //button is released
             isWalking = false;
         }
     }
 
     public void Jump(InputAction.CallbackContext context)
     {
         ChangeAnimationState(PLAYER_JUMP);
         if (context.performed && IsGrounded())
         {
             rb.velocity = new Vector2(rb.velocity.x, jumpingPower);
         }
 
         if (context.canceled && rb.velocity.y > 0f)
         {
             rb.velocity = new Vector2(rb.velocity.x, rb.velocity.y * 0.5f);
         }
     }
 
     public void Attack(InputAction.CallbackContext context)
     {
         if (context.performed)
         {
             if (isShooting) return;
 
             //shoot
             //ChangeAnimationState(PLAYER_ATTACK);
             //animator.Play("Player_throw");
             isShooting = true;
             isAttackPressed = true;
             ColliderPlayer.SetActive(true);
             ColliderCrouch.SetActive(false);
             crouch = false;
             audioSource.PlayOneShot(ThrowClip, 0.5F);
 
             //instantiate and shoot bullet
             GameObject b = Instantiate(bulletPrefab);
             b.GetComponent<KnifeScript>().StartShoot(isFacingLeft);
             b.transform.position = bulletSpawnPos.transform.position;
 
             Invoke("ResetShoot", shootDelay);
         }
     }
 
     void ResetShoot()
     {
         isShooting = false;
     }
 
     public void SetBulletPrefab(GameObject newBullet)
     {
         bulletPrefab = newBullet;
     }
 }