How to write an annotation to a step entity

Hi Bros, I get a face's annotation of a step entity.

Just like this:

#17 = ADVANCED_FACE('233',(#18),#32,.F.);

I get the "annotation ": 233. (I don't know it's term, and just call it "annotation ")

I get the annotation through class StepRepr_RepresentationItem. And there is my code:

std::string filepath = "C:\\Users\\14656\\Desktop\\Program\\Open Cascade\\Demo_LRH\\build\\box_hole.step";

    //! 1、
    STEPControl_Reader reader;
    //! 2、
    //! 3、
    //! 4、
    TopoDS_Shape shape = reader.OneShape();

    Handle(XSControl_TransferReader) treader = reader.WS()->TransferReader();
    for (TopExp_Explorer exp(shape, TopAbs_FACE); exp.More(); exp.Next())
        TopoDS_Shape face = exp.Current();
        Handle(Standard_Transient) entity = treader->EntityFromShapeResult(face, 1);
        Handle(StepRepr_RepresentationItem) repre = Handle(StepRepr_RepresentationItem)::DownCast(entity);
        if (!repre.IsNull())
            if (!repre->Name().IsNull())

                std::string name = repre->Name()->ToCString();
                std::cout << name<< std::endl;

Now, there is my question, how to set the annotation and save it in .step file. Actually, I can use the StepRepr_RepresentationItem.SetName() to set the annotation, however, it didn't saved in .step file.

The scenes is that I make a box through BRepPrimAPI_MakeBox, so I get the box's TopoDS_Shape, and then I will save it to box.step. Meanwhile, I want to set the annotation for every face, I have no idea how to complete it.