question about asset chunk

I am studying asset chunking to implement patch update system.
The larger and more complex projects, the more assets I use will be more than I can imagine.
Should I designate a Primary Asset Label for all of them?
In particular, I have more folders because I have categorized blueprints, widgets, levels, and textures that I use by purpose.

https://docs.unrealengine.com/5.1/en-US/implementing-chunkdownloader-in-your-gameplay-in-unreal-engine/

I am referring to this document and creating it. ‘DELLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam’ is said to have no function definition.