[HELP] SAssetDropTarget not showing up in editor

I am trying to customize a Property using IPropertyTypeCustomization.

This property looks like this:

struct BMOVE_API FTaskSelection 

	UPROPERTY(EditInstanceOnly, BlueprintReadWrite)
	AActor *										Task;
	UPROPERTY(EditInstanceOnly, BlueprintReadWrite)
	TArray<FString>                                                                LocomotionSelections;

In my CustomizeHeader method, I’d like a SAssetDropTarget next to a TextComboBox. For the SAssetDropTarget I do something like:

		StructPropertyHandle->CreatePropertyNameWidget(LOCTEXT("Change", "Task"), LOCTEXT("IDK", "IDK"), false, true, false)
			.OnIsAssetAcceptableForDrop(this, &FTaskSelectionDataCustomization::IsAssetAccetableForDrop)

However, if I do this, nothing shows up in the editor! I get a SNullComponent inside the SAssetDropTarget. How do I set this up correctly???

Please Advise!