Non-Domain User Password Management?

I am on the current version of Password Manger and have a question. We have a use-case where we need to manage user passwords from a system that does not have a connection to Active Directory. Can Password Manager manage users that are in a system like a RADUIS or a web-based Security Accounts Manager (SAM) system? Is the Quick-Connect system (that I'm having trouble finding documentation) the answer? If so, can someone point me in the right direction to a tutorial or admin guide?

Any help is much appreciated!