Microsoft does offer an official "portable" version of Office LTSC Professional Plus 2021 Go to product viewer dialog for this item.
Portable apps do not update automatically via Windows Update. To get the latest security patches, you usually have to download a newer version of the portable package. How to Use Office 2021 Portable microsoft office ltsc pro plus 2021 portable
This combination of keywords represents the holy grail for many professionals. "LTSC" promises stability without feature changes. "Pro Plus" offers the full arsenal of apps. "2021" is the modern, proven version. And "Portable"? That means no registry entries, no leftovers, and run-from-anywhere capability. not Microsoft does offer an official "portable" version