ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_NOT_ALLOWED: The 'dockerfile_path' field applies only to Dockerfile builds - ngrok documentation

What does ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_NOT_ALLOWED mean?

ngrok returns ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_NOT_ALLOWED with this message:

The 'dockerfile_path' field applies only to Dockerfile builds.

Where can I get more help with ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_NOT_ALLOWED?

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