Installing Rosetta 2 on this system is not supported.

I'm trying to install Rosetta 2 on a several unmanaged Macbook Air M1 running Max OSX 10.16 and I am getting the error "Installing Rosetta 2 on this system is not supported."

I've treid the following commands, all to no avail, and all generating the same error:

1. /usr/sbin/softwareupdate --install-rosetta
2. /usr/sbin/softwareupdate --install-rosetta --agree-to-license
3. sudo /usr/sbin/softwareupdate --install-rosetta --agree-to-license

Help!

PS - Apple support page says "You're asked to install Rosetta the first time you open an app that needs Rosetta" which is NOT true. The 2 apps we have that need Roestta are (also) not apps that users interact with (centralized Anti-Virus and Remote Access/Control), so they DONT prompt you to install it. It HAS to be installed manually.