Managed Service Accounts isn't a feature of a Windows Server but of an Active Directory.
MSA’s allow you to create an account in Active Directory that is tied
to a specific computer.
And this is how it works:
The Windows Server 2008 R2 AD Schema introduces a new object class
msDS-ManagedServiceAccount. - -
The object is a user and a
computer at the same time, just like a computer account. But it does
not have an object class of person like a computer account typically
would; instead it has
msDS-ManagedServiceAccount. MSA’s inherit from
a parent object class of “Computer”, but they are also users. - -
An MSA is a quasi-computer object that utilizes the same password update mechanism used by computer objects. So, the MSA account password is updated when the computer updates its password.
So it is impossible to have MSA's without a domain and the AD DS Administration Cmdlets only works on a Domain Controller. (It's a hint that every single one has
AD in it, like
If you don't want to have this demo environment as a part of your existing domain, you could easily create a separated demo domain (or use Virtual Accounts instead, like mentioned in comments). Creating a new domain could be an option if the purpose of your demo server is to test your configuration on an identical environment before using it in production.