Open content from Google Ad SDK inside app browser Flutter

Question

That is initialisation of banner ad.

   _bannerAd = BannerAd(
      adUnitId: adUnitId,
      request: const AdRequest(),
      size: bannerSize1,
    )..load();

That is ad widget.

   SizedBox(
            width: bannerSize1.width.toDouble(),
            height: bannerSize1.height.toDouble(),
            child: AdWidget(ad: _bannerAd!),
          )

When I click on add, then content opens on system browser, but I need get link and open it by myself in app browser, to nor leave the app. Haw to get link for content, or at least open browser inside app with this content?

 final link3 = _bannerAd3?.request;
 final link2 = _bannerAd3?.request.contentUrl;
 final link = _bannerAd3?.request.neighboringContentUrls;

All of this stuff are null.