As the example shows, the users to be removed from the Information Barrier group (specified as a list of user IDs) must be included in the data parameter.
It is currently not possible to remove a deactivated user from an IB group via the API. Please use the Admin Portal if you wish to do this.
Roles and Privileges
Calling this endpoint requires the ACCESS_USER_PROVISIONING_API privilege.
See Bot Permissions for a list of roles and associated privileges.