Update NERM - System User Internal Attributes

Hi All, does anybody have insights on how to update the system users in NERM except from UI directly?

The native file upload on the UI under System tab > Users, allows us to create users with only Name, Email, Login, Roles, Status fields but I’m also looking to update the nested fields inside it maybe using the CSV upload but was unable to do so. Based on my exploration, I did not find any REST APIs as well which would allow us to update, for example the “MANAGERS” or “MANAGED USERS” fields once we click on the system user.

Also by any chance, is there a way the “MANAGERS” field can be mapped with the user’s manager on IdentityNow to facilitate any approvals?

Would really appreciate any inputs here.

Thanks,
Arshad.