Make bullet fly exactly in the center of screen

Hi everyone. could someone explain me how can i shoot exactly in the center of the screen from any position? I have here my character in third person. The camera rotates with a free looking cinemachine camera. The red sphere is the fire origin. The grey sphere is the current bullet. And the white dot is where i want the bullet to go. No Matter in which direction i rotate. Could someone help?

https://i.imgur.com/lVwQIb0.png

   void Shoot(){
         Ray mouseRay =  GetComponent<PlayerBase>().cam.ScreenPointToRay(Input.mousePosition);
         float mouseDir = ( GetComponent<PlayerBase>().transform.forward -  GetComponent<PlayerBase>().cam.transform.position).magnitude * 1f;
         GetComponent<PlayerBase>().shootOrigin.transform.LookAt(mouseRay.origin + mouseRay.direction * mouseDir);
        
         Instantiate(attack[0], GetComponent<PlayerBase>().shootOrigin.position, GetComponent<PlayerBase>().shootOrigin.rotation);
     }