include private header "Sequencer/Private/SequencerSelection.h" causes an error

I’m using Unreal Engine 5.0.3.

I need a type in a private folder called FSequencerSelection, so I included it.

But then there was an error.

...\VMDImporter.cpp(13): fatal error C1083: Cannot open include file: 'SequencerSelection.h': No such file or directory

So, I added a private include path through the search as follows.

var engineSourceDirectory = Path.GetFullPath(Target.RelativeEnginePath);

PrivateIncludePaths.AddRange(
    new string[]
    {
        Path.Combine(engineSourceDirectory, "Source/Editor/Sequencer/Private"),
        // ... add other private include paths required here ...
    }
);

Then, there’s a linking error.

1>VMDImporter.cpp.obj : error LNK2019: unresolved external symbol "public: class TSet<class TSharedRef<class FSequencerDisplayNode,1>,struct DefaultKeyFuncs<class TSharedRef<class FSequencerDisplayNode,1>,0>,class FDefaultSetAllocator> const & __cdecl FSequencerSelection::GetSelectedOutlinerNodes(void)const " (?GetSelectedOutlinerNodes@FSequencerSelection@@QEBAAEBV?$TSet@V?$TSharedRef@VFSequencerDisplayNode@@$00@@U?$DefaultKeyFuncs@V?$TSharedRef@VFSequencerDisplayNode@@$00@@$0A@@@VFDefaultSetAllocator@@@@XZ) referenced in function "public: static void __cdecl FVmdImporter::ImportVmdCamera(struct FVmdParseResult const &,class UMovieSceneSequence const *,class ISequencer &,bool)" (?ImportVmdCamera@FVmdImporter@@SAXAEBUFVmdParseResult@@PEBVUMovieSceneSequence@@AEAVISequencer@@_N@Z)
1>D:\noname\Projects\GitHub\MmdImporterPlugin\Plugins\MMDCameraImporter\Binaries\Win64\UnrealEditor-MMDCameraImporter.dll : fatal error LNK1120: 1 unresolved externals

The error accrued from the code FSequencerSelection::GetSelectedOutlinerNodes method. build succeeded when remove this code.

This is the code in question.

//...
#include "SequencerSelection.h"
//...
void FVmdImporter::ImportVmdCamera(
	//...
	const UMovieSceneSequence* InSequence,
	//...
)
{
	//...
	FSequencerSelection& SequencerSelection = InSequencer.GetSelection();

	SequencerSelection.GetSelectedOutlinerNodes();
}

Here’s the link to full source.

I’ve been searching and trying all day, but it really doesn’t work out. Please help.