This it's on you. I created a VM with virt-manager (it may be annoying) you can copy the xml located in /etc/libvirt/qemu/vm-name.xml and edit it manually and start it with virsh create windows.xml or just edit the XML with sudo virsh edit win10; if you change any settings within virt-manager the XML may be rewritten.
Do NOT use windows.xml from the repo it's only there to show how it could be done. IT WON'T WORK. Always create a new XML with virt-manager.
You have to create a network. I created it with virt-manager and dumped the xml with sudo virsh net-dumpxml virt1 where virt1 is the name of the network.
Create the network with sudo virsh net-create virsh-network.xml and remove it with sudo virsh net-destroy virt1.