ajax请求时cookie设置不成功

public function index(Request $request)
    {
        $startTime = microtime(1);

        $response = response();

        $geo = [
            'code' => 1,
            'data' => [
                'ip' => $request->header('x-real-ip'),
                'ua' => $request->header('user-agent'),
                'ref' => $request->header('referer'),
            ],
            'cache' => 1,
            'msg' => 'success'
        ];

        $ccCookieName = md5($geo['data']['ip']);
        $geo['data']['cc'] = $request->cookie($ccCookieName);

        if ($geo['data']['cc'] === null)
        {
            $geo['cache'] = 0;
            $geoIp = new Reader(config('app.database_path') . '/GeoLite2-Country.mmdb');
            try {

                $geo['data']['cc'] = $geoIp->country($geo['data']['ip'])->country->isoCode;
                $response->cookie($ccCookieName, $geo['data']['cc'], 7 * 24 * 3600, '/', '.domain.com');

            } catch (AddressNotFoundException|InvalidDatabaseException $e) {

                $geo['code'] = 0;
                $geo['msg'] = $e->getMessage();
            }
        }

        $geo['time'] = microtime(1) - $startTime;

        return $response
            ->header('Content-Type', 'application/json')
            ->withBody(json_encode($geo, JSON_UNESCAPED_UNICODE));
    }

我直接通过浏览器访问这个页面时，cookie设置是成功的，但当我通过ajax请求这个页面时，cookie设置不成功 请问是什么原因？
发起ajax请求的域名是domain.com，被请求的域名是api.domain.com