Here is a helpful review regarding the download process and the software itself.
Apple Configurator 2 DMG files are not publicly distributed by Apple; the application is primarily available as a free download through the Mac App Store apple configurator 2 dmg file download
Tip: prefer the Mac App Store for easiest updates; use Apple support downloads only if you need an offline or specific older version. Here is a helpful review regarding the download
Apple does not officially provide Apple Configurator 2 as a standalone file; it is exclusively distributed through the Mac App Store Official Download Method apple configurator 2 dmg file download