how can I move my first person camera by mouse

I try to make a fps that will make the camera rotate by Q and E but I can not move the camera by mouse. here my code: using UnityEngine;

 public class Player : MonoBehaviour {
 
     private MazeCell currentCell;
 
     private MazeDirection currentDirection;
 
     public void SetLocation (MazeCell cell) {
         if (currentCell != null) {
             currentCell.OnPlayerExited();
         }
         currentCell = cell;
         transform.localPosition = cell.transform.localPosition;
         currentCell.OnPlayerEntered();
     }
 
     private void Move (MazeDirection direction) {
         MazeCellEdge edge = currentCell.GetEdge(direction);
         if (edge is MazePassage) {
             SetLocation(edge.otherCell);
         }
     }
 
     private void Look (MazeDirection direction) {
         transform.localRotation = direction.ToRotation();
         currentDirection = direction;
     }
 
     private void Update () {
 
 
 
         if (Input.GetKeyDown(KeyCode.W) || Input.GetKeyDown(KeyCode.UpArrow)) {
             Move(currentDirection);
         }
         else if (Input.GetKeyDown(KeyCode.D) || Input.GetKeyDown(KeyCode.RightArrow)) {
             Move(currentDirection.GetNextClockwise());
         }
         else if (Input.GetKeyDown(KeyCode.S) || Input.GetKeyDown(KeyCode.DownArrow)) {
             Move(currentDirection.GetOpposite());
         }
         else if (Input.GetKeyDown(KeyCode.A) || Input.GetKeyDown(KeyCode.LeftArrow)) {
             Move(currentDirection.GetNextCounterclockwise());
         }
         else if (Input.GetKeyDown(KeyCode.Q)) {
             Look(currentDirection.GetNextCounterclockwise());
         }
         else if (Input.GetKeyDown(KeyCode.E)) {
             Look(currentDirection.GetNextClockwise());
         }
     }
 }