It is also possible to generate a Factur-X file directly, without the <FACTUR-X> tag.
Steps :
1.Create a PDF file that complies with the PDF-A/3 standard:
<PDF-A/3B>
2.Add the .xml file:
<PDF-ATTACH=file_name [,id=ident] [.desc=description]>
Additional files:
You can add other external files using the <PDF-ATTACH> tag.