Scroll down on that page. They are a Microsoft-Verified Partner and note: “Please check all system requirements before purchasing. Check your computer compatibility with Windows 11 here
This version is designed for PCs that need a new license for Windows and meet the minimum system requirements for Windows 11. If your PC is running Windows 10 and you are unable to use Windows Update to install the free upgrade to Windows 11, you will not be able to install this version of Windows 11.”
It worked for me Win 10 Home to Win 11 Pro.
George