ERR_NGROK_SHIP_PUBLISH_TARGET_HOST_NOT_ALLOWED: The 'host' field must be empty for a builtin publish target - ngrok documentation

What does ERR_NGROK_SHIP_PUBLISH_TARGET_HOST_NOT_ALLOWED mean?

ngrok returns ERR_NGROK_SHIP_PUBLISH_TARGET_HOST_NOT_ALLOWED with this message:

The 'host' field must be empty for a builtin publish target. ngrok manages its host.

Where can I get more help with ERR_NGROK_SHIP_PUBLISH_TARGET_HOST_NOT_ALLOWED?

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