Readiness 24 C - Payment Confirmation Acknowledgements Using a REST API

Why are the attributes IBY Payment Status, Invoice Amount, and Invoice Payment Amount not available for update via the API?
The documentation indicates that updating the acknowledgment status via API is a supported feature, but this functionality is actually not supported. Can you clarify this discrepancy?

This is the link with the feature description:

This is the link to the API documentation:

The IBY Payment Status, Invoice Amount, and Invoice Payment Amount fields are not listed as request body attributes.

API Test: