ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_FILE_REQUIRED: The 'dockerfile_path' value VALUE must name a file - ngrok documentation

What does ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_FILE_REQUIRED mean?

ngrok returns ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_FILE_REQUIRED with this message:

The 'dockerfile_path' value <VALUE> must name a file.

Where can I get more help with ERR_NGROK_SHIP_BUILD_CONFIG_DOCKERFILE_PATH_FILE_REQUIRED?

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