Rotating weapon in top-down 2D

I'm working on a 2D top-down shooter, and I want to use controller to rotate weapon direction. For now I got only mouse controls.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class WeaponRotation : MonoBehaviour
 {
 
     public Rigidbody2D rb;
     public Camera cam;
 
     Vector2 movement;
     Vector2 mousePos;
 
     void Update()
     {
         mousePos = cam.ScreenToWorldPoint(Input.mousePosition);
     }
 
     void FixedUpdate()
     {
         Vector2 lookDir = mousePos - rb.position;
         float angle = Mathf.Atan2(lookDir.y, lookDir.x) * Mathf.Rad2Deg - 0f;
         rb.rotation = angle;
     }
 }