If your VM has no internet, download from :

virt-install --name windows11 --ram 8192 --cpu host \ --disk path=/var/lib/libvirt/images/windows11.qcow2,format=qcow2 \ --cdrom /path/to/Win11.iso --os-variant win10 --graphics spice \ --features kvm_hidden=1 --boot uefi

Finding a pre-built Windows 11 .qcow2 file is difficult because Microsoft does not officially distribute Windows in that format. Instead, you should download the official and convert it or use it to create your own image. 1. Recommended Method: Build Your Own