warningFactur-X / ZUGFeRD containercontainerPDF
The XMP metadata must contain the Factur-X or ZUGFeRD extension schema.
XMP metadata is present but contains no Factur-X or ZUGFeRD extension schema.
Add the fx: schema (urn:factur-x:pdfa:CrossIndustryDocument:invoice:1p0#) with DocumentType INVOICE, DocumentFileName, Version and ConformanceLevel.