building a flutter widget starting from existing native code (ios/android)

The project is about to wrap/host an existing SDK (currently available in native language for android anc ios) So we can use it in our flutter project as widget.

The SDK is an interface to ad ADS provider providing us preconfigured endpoints and show different kind of banners. Documentation and source code are available.

Deliverables
Provide a working example Flutter app source code with banner widgets.