May I know how to intercept some functionality before sendLoginResponse()?

May I know how to intercept some functionality before sendLoginResponse()?
I want to check if $request contains link or not. Right after login validation.
I tried to use dd() but it is not working.
 

protected function sendLoginResponse(Request $request)

{

    dd("Stop here");

    $request->session()->regenerate();

    $this->clearLoginAttempts($request);

    return $this->authenticated($request, $this->guard()->user())

            ?: redirect()->intended($this->redirectPath());

}