I want to backup the Nutanix AHV VMs, ，but I dont’t kown how to get the list of changed data blocks.

In this article (Nutanix 5.0 Features Overview (Beyond Marketing) – Part 2), I see the following:

Nutanix CBT utilizes the new REST 3.0 API that can be used to query for the changed meta-data regions given any two snapshots of a virtual disk or virtual machine. The approach is valuable for taking incremental and differential backups; and even useful while taking full backups because the API identifies regions that are spare (zeroed), therefore saving on read operations.

I read the api documentations (PRISM v2.0 and PRISM v3) carefully, But I don’t see find a useful api.

Does anyone tell me which API to use how to use it?

Thank you.