ERR_NGROK_211: The METHOD request you made does not expect a body, but you provided one - ngrok documentation

What does ERR_NGROK_211 mean?

ngrok returns ERR_NGROK_211 with this message:

The <METHOD> request you made does not expect a body, but you provided one. Check your API client implementation and review the API documentation: https://ngrok.com/docs/api-reference/.

Where can I get more help with ERR_NGROK_211?

Email support@ngrok.com and include the error code.