Closing Web Messaging session from backend

Trying to end a Web Messaging session via the backend API. Calling DELETE /api/v2/conversations/messaging/instances/{id} but getting a 400 Bad Request. The payload is empty. Docs are vague on the required body for termination.

Is there a specific JSON payload needed to force close the session grammatically? Or is this endpoint only for internal cleanup and I should just let the client side timeout handle it? Stuck on this integration.