Thanks @David Benson [draw.io] for the link to this tutorial. However, something does not work for me.
You can also right click on the Gliffy diagram and select "View Source"
=> This is ok, so I copy the source code (JSON format).
In a new draw.io diagram press ctrl/cmd-V to insert the Gliffy diagram
=> Where do I paste this JSON snippet? There is a textarea in the 'Options' / 'Advanced' / 'Edit' menu. But if I paste the JSON snippet in it and click "OK", no content is added.
Thanks in advance,