If you need a VHD for "native boot" or testing, the standard process is to create one manually: Download Windows 11 - Microsoft
If you are looking for the actual files described in this story, you can find official, pre-made virtual machines (VHDs) directly from Microsoft: windows 11 vhd download link
Always build your own using the instructions above, or download the official 90-day developer VHDX directly from the Microsoft domain. If you need a VHD for "native boot"