Character Motion And Animation script for Unity

CharacterMotionAndAnimation.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CharacterMotionAndAnimation : MonoBehaviour
{
    public Animator animator;
    public GameObject camera;
    public CharacterController controller;
    public Vector3 playerVelocity;
    private bool groundedPlayer;
    private float runSpeed = 5.0f;
    private float playerSpeed = 2.0f;
    private float jumpHeight = 1.0f;
    private float gravityValue = -9.81f;
    private bool isIdle = true;
    private float horizontalAxis = 0;
    private bool jumping = false;
    private bool moving = false;
    private bool running = false;
    private float verticalAxis = 0;
    void FixedUpdate()
    {
        var forward = camera.transform.forward;
        var right = camera.transform.right;

        forward.y = 0f;
        right.y = 0f;
        forward.Normalize();
        right.Normalize();
        
        var desiredMoveDirection = forward * verticalAxis + right * horizontalAxis;

        groundedPlayer = controller.isGrounded;
        if (groundedPlayer && playerVelocity.y < 0)
        {
            playerVelocity.y = 0f;
        }

        Vector3 move = forward * verticalAxis + right * horizontalAxis;
        controller.Move(move * Time.deltaTime * (running ? runSpeed : playerSpeed));
        moving = move != Vector3.zero;
        if (moving)
        {
            gameObject.transform.forward = move;
        }

        playerVelocity.y += gravityValue * Time.deltaTime;
        controller.Move(playerVelocity * Time.deltaTime);
    }
    void Update()
    {
        groundedPlayer = controller.isGrounded;
        horizontalAxis = Input.GetAxis("Horizontal");
        verticalAxis = Input.GetAxis("Vertical");
        running = Input.GetButton("Fire2") == true;
        if (jumping == false && groundedPlayer == false && playerVelocity.y <= -3)
        {
            isIdle = true;
            jumping = true;
            animator.Play("jump", 0);
        }
        else if (Input.GetButtonDown("Jump") && groundedPlayer)
        {
            isIdle = true;
            // animator.Play("jump", 0);
            playerVelocity.y += Mathf.Sqrt(jumpHeight * -3.0f * gravityValue);
            jumping = true;
            animator.Play("jump", 0);
        }
        else if (jumping && groundedPlayer && playerVelocity.y <= 0)
        {
            animator.Play("land", 0);
            jumping = false;

        }
        else if (moving && groundedPlayer == true && playerVelocity.y <= 0)
        {
            if (isIdle == true)
            {
                isIdle = false;
            }
            if (running == true)
            {
                animator.Play("run");
            }
            else
            {
                animator.Play("walk");
            }
        }
        else if (isIdle == false && groundedPlayer == true)
        {
            isIdle = true;
            animator.Play("idle");
        }
    }

}