1st Person Character Controller X Axis not working

I can move the camera with my mouse up and down, but not left and right. This is the script I’musing PLS HELP.

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

public class mouse_look : MonoBehaviour
{

public float mouseSensitivity = 100f;

public Transform playerBody;

float xRotation = 0f;

// Start is called before the first frame update
void Start()
{
    Cursor.lockState = CursorLockMode.Locked;
}

// Update is called once per frame
void Update()
{
    float mouseX = Input.GetAxis("Mouse X") * mouseSensitivity * Time.deltaTime;
    float mouseY = Input.GetAxis("Mouse Y") * mouseSensitivity * Time.deltaTime;

    xRotation -= mouseY;
    xRotation = Mathf.Clamp(xRotation, -90f, 90f);

    transform.localRotation = Quaternion.Euler(xRotation, 0f, 0f);
    playerBody.Rotate(Vector3.up * mouseX);
}

}

I think you assignd the variable playerBody to the player and not the parent object. I am guessing you are following brackeys firstperson tutorial. Sorry for bad english.