The situation:

The latest npm release of the D-ID agents SDK points to your dev environment API URL instead of production, so createAgentManager cannot connect to the API at all. Every connection attempt fails because it is hitting the wrong backend. Is there a fixed version I should be using?

What actually fixes it (verified in the thread):

You are right, that release accidentally shipped with the dev environment API URL baked in, so nothing could connect. The team has fixed it, so update to the latest version of the package and createAgentManager will hit the production API again. If you are pinned to the broken version, bumping the version is the fix. Source: https://github.com/de-id/agents-sdk/issues/151