Hi,
solved it myself.
Changed interface to
<?xml version="1.0" encoding="UTF-8" ?>
<ns0:MT_Addenda xmlns:ns0="http://www.sat.gob.mx/cfdi/1">
<File>
<Line>Text1</Line>
<Line>Text2</Line>
</File>
</ns0:MT_Addenda>
and set parameters in content conversion of receiver adapter as follows:
Thanks
Elko