If I use a NErmShape and call mappingShape.SizeToContent();
The result is like the attachment?
Is there any solution to really fit first line?

Erm shapes automatically resize themselves to their content, but in order for the autosize to work you must add them to a drawing document first.

Best Regards,
Nevron Support Team

It's what I have done
nDrawingDocument1.ActiveLayer.AddChild(mappingShape);
NStyle.SetTextStyle(mappingShape, new NTextStyle(fontStyle, Color.Black));
mappingShape.Style.TextStyle.StringFormatStyle.HorzAlign = Nevron.HorzAlign.Left;
mappingShape.SizeToContent();

But the text is still on 2 lines

Solved using courrier new font arial give unexpected results