Microsoft no longer prominently features older builds like 21H2 on the front page of the Windows download site. By default, they push the latest version of Windows 10 (22H2) or Windows 11. However, the 21H2 ISO is still accessible via the for enterprise and technical users.

Click the icon (looks like a phone/tablet) or change the User Agent to "Chrome - iPad" or "Android" in the Network Conditions tab.

Microsoft typically prioritizes the latest version (currently 22H2) on its public download page. However, you can still obtain 21H2 through official channels: