public class FireCtrl : MonoBehaviour
{
    public GameObject bullet;
    public Transform firePos;

    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            Fire();
        }
    }
    void Fire()
    {
        CreateBullet();
    }
    void CreateBullet()
    {
        Instantiate(bullet, firePos.position, firePos.rotation);
    }
}