Get the list of supported header names.

The names that are returned can be used as the headers for the CSV file.
The filter query parameter supports the options:

"user" - the filter shows the user header names.
"group" - the filter shows the group header names.

No filter shows the user header names.

Entitlement required: manageUserGroups (Manage users and groups) or manageAllUserGroups (Synchronize users and groups) or manageUserStandardGroups (Manage users and standard groups).
Note: You only need one entitlement, but you can have more than one.