If have installed gnome-boxes from manjaro official repository on my Manjaro KDE Plasma host system. On boxes I have intalled Manjaro XFCE. It works so far. In the settings of the new virtual machine (Manjaro XFCE) I have given access to my host folders (settings → devices & shares → shared folders). See attachments.
Also keep in mind that you need to set up the SPICE vdagent in your guest OS. And of course you need to use the Spice protocol to connect to the guest.
Last time I checked Gnome Boxes uses spice-webdav , so you really need the SPICE tools in your guest OS.
Thanks. I have found this description already before. But the setting seems not to exist.
I must be already preinstalled and no more settings do exist. I did not understand that the clipboard only works for text and pictures, e.g. screenshots. Not more.
FILES TRANSFER
I have found out that you can even get files from host to guest without extra samba and spice settings on the host. In the guest system select on the top right (3 vertical buttons). The first line it is written send files. (see attachment). But it is actually just an upload from the host to the guest not vice versa. Of course in the guest settings you have to give access first to specific folders on your host system.
CLIPBOARD
I found SPICE vdagent is already automatically preinstalled on the guest system. I did not install it on the guest system.
But what settings and how do I need to make in spice vdagent, spice protocol set up and may be spice-webdav?
However. What still does not work is to “send” / transfer files from the guest system to the host system in boxes!!