Update knowledge base links and metadata via API

I would like to update the links and metadata fields of an existing knowledge base using the HeyGen API.

Currently, the Update Knowledge Base
endpoint only supports updating name, opening, and prompt. However, there is no clear documentation on how to modify links or metadata once the knowledge base has been created.

Questions

Is there an API endpoint that allows updating links of a knowledge base after creation?

How can I add or update custom metadata for a knowledge base?

If not supported, are there any recommended workarounds (e.g., deleting and recreating the knowledge base with the new links/metadata)?