keep live api not working

Hi, Im trying working with HeyGen Stream API. For now im able to create to create new session and start session, i want keep session to live so i called keep live api "v1/streaming.keep_alive“, but it's not working even i put session_id to keep live api, i got ”{"status": "error", "message": "Failed to keep session live: 400", "details": "{"code":10002,"message":"invalid session state: closed"}"}" this error after call keep live api