Player Controller

//Player Move
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerController : MonoBehaviour
{
    private CharacterController _controller;
    private Vector2 _playerVelocity;
    private bool _groundedPlayer;

    public float _gravityValue;
    public float playerSpeed;
    public float jumpHeight;

    private void Start()
    {
        _controller = GetComponent<CharacterController>();
    }

    void FixedUpdate()
    {
        _groundedPlayer = _controller.isGrounded;

        if (_groundedPlayer && _playerVelocity.y < 0)
        {
            _playerVelocity.y = 0f;
        }

        Vector2 move = new Vector2(Input.GetAxis("Horizontal"), 0);
        _controller.Move(move * Time.fixedDeltaTime * playerSpeed);

        if (move != Vector2.zero)
        {
            gameObject.transform.forward = move;
        }

        if (Input.GetKey(KeyCode.X))
        {
            _controller.Move(move * Time.fixedDeltaTime * playerSpeed * 1.5f);
        }


        if (Input.GetKey(KeyCode.Space) &&  _groundedPlayer)
        {
            _playerVelocity.y += Mathf.Sqrt(jumpHeight * -3.0f * _gravityValue);
        }

        _playerVelocity.y += _gravityValue * Time.fixedDeltaTime;
        _controller.Move(_playerVelocity * Time.fixedDeltaTime);
    }
}