A 401 error is returned when a Management API call is made to the CASB tenant to do a user operation like update user or delete user.
Ensure that a ending slash / is at the end of the query.
For example
https://api-vip.elastica.net/<casb tenant name>/api/admin/v1/user_management/
and not
https://api-vip.elastica.net/<casb tenant name>/api/admin/v1/user_management