Need more information about using UE as an external library

I know UE4.27 bring a new feature named " Unreal Engine as a Library" ,it makes it possible to build the UE4 runtime as a library and interact with build-in API, my program use UE4 engine as background image generator,I think this feature is meeting my needs, But I only find one document about the feature(Building Unreal Engine as a Library | Unreal Engine 4.27 Documentation), and I could not find the samples in the document.
I really need this feature,so is there any more documents and samples about it?