This video shows users how to change from Windows S mode to Windows Home mode allowing you to install applications that are not from the Windows store. This applies to Windows 10 and Windows 11. In this example we use this mode change to install Google Chrome which currently isn't in the Microsoft Store.
I personally think that having to do this switch via logging in is completely over the top, there should have just been a switch in preferences to allow external sources to be installed, but as usual it is about control, and that is something Microsoft likes.
Be warned that signing out of the account the did the switch from S mode to Home, can revert Windows back to S mode again. So if you're activating for someone else, don't use your Microsoft account to activate.