Overtrue\Socialite\Providers\AbstractProvider::redirect PHP Метод

    public function redirect($redirectUrl = null)
    {
        $state = null;
        if (!is_null($redirectUrl)) {
            $this->redirectUrl = $redirectUrl;
        }
        if ($this->usesState()) {
            $state = sha1(uniqid(mt_rand(1, 1000000), true));
            $this->request->getSession()->set('state', $state);
        }
        return new RedirectResponse($this->getAuthUrl($state));
    }