Cannot send event through NewRelic Python Package

I keep getting
2021-11-21 11:30:07,496 (21998/NR-Activate-Session/sim_info_server) newrelic.core.agent_protocol WARNING - Received a non 200 or 202 HTTP response from the data collector where params={‘protocol_version’: 17, ‘marshal_format’: ‘json’, ‘method’: ‘preconnect’}, headers={‘Content-Type’: ‘application/json’}, status_code=503 and content=b’{}’.

I don’t know where goes wrong.

  1. I installed the PIP package newrelic,
  2. download the init file.
  3. start python app with newrelic prefixed command

Still getting errors in log file