I think you need the UM API.Have a look here:Getting Started with User
ManagementIf you require help on this specific topic, open a support
case inside the Admin Console -> Support menu and ask for developer
support on User Management API if the documentation is not
sufficient.EDIT: the UM API will not help on getting events on who is
using or who is not using a subscription, rather who is assigned or not
to a Product, add/remove/update accounts in Admin Console, get
information about Org's grou...