Since no codes given online to QEMU/KVM or to GNOME-Boxes works -due to FlatPak (which is a great thing fromthe security side)- I can’t change what GNOME-Boxes emulates /virtualies. (I only can determine how much memory and Hard Disk space can a Virtual Machine use). I need to know exactly what Video Adapter (or Video Card) does GNOME-Boxes emulate by default in order to get the drivers to it.
What video adapter does GNOME-Boxes virtualize / emulate?
Thank you very much have a nice day! 
@garpe Ask the GNOME Boxes developer https://gitlab.gnome.org/GNOME/gnome-boxes/issues