Hello raritz121,
it is discussed on the XFCE forum here - https://forum.xfce.org/viewtopic.php?id=7185
It is also an older thread, it is marked as SOLVED, there may be newer thread on the subject on the XFCE forum link.
It uses the same manual method as described on the link in my first reply, but as it is the XFCE forum they may have additional information ?
https://forum.xfce.org/search.php?search_id=1398977431
https://forum.xfce.org/search.php?search_id=1380974798
it is discussed on the XFCE forum here - https://forum.xfce.org/viewtopic.php?id=7185
It is also an older thread, it is marked as SOLVED, there may be newer thread on the subject on the XFCE forum link.
It uses the same manual method as described on the link in my first reply, but as it is the XFCE forum they may have additional information ?
https://forum.xfce.org/search.php?search_id=1398977431
https://forum.xfce.org/search.php?search_id=1380974798