StaticMeshEditorExtension plugin has no .generated.h ? (UE4-27)

I’m using #include “UVTools/UVGenerationFlattenMapping.h” in my cpp. But complie error:
“UVGenerationFlattenMapping.generated.h’ file not found”。
I found this plugin (StaticMeshEditorExtension) has no ‘Inc’ directory in ‘Intermediate’ directory(/Volumes/wdssd/Applications/UE/UE_4.27/Engine/Plugins/Enterprise/StaticMeshEditorExtension/Intermediate), so it has no .generated.h. Why?
[UE4-27](not the source code version)