How to declare a public dependency in a Blueprint-only project?

This question is related to the issue of TAssetPtr not accepting UPaperSprite as a type, when a UPaperSprite is loaded as a Content Reference from a DataTable: Why won't TAssetPtr won't accept UPaperSprite as a type - Asset Creation - Epic Developer Community Forums

I have a Blueprint-only project, which I’d like to keep that way, and I need to use a DataTable with UPaperSprite Content References. I want to have the DataTable use a Struct with UPaperSprite objects, but the problem is (from the above referenced question):

I’m able to get the Content Reference to work in the DataTable by making the
TAssetPtr use UObject (TAssetPtr<
UObject >), but then I have to cast
the resolved Asset ID from an Object
to a Paper2DSprite each time I want to
get the Paper2D Sprite out of the

The documentation says UPaperSprite is
a UCLASS (see:

The posted solution was to add Paper2D as a public dependency in ProjectName.Build.cs. This is great. But: how do I do that in a Blueprint-only project, when there isn’t a Build.cs file?