ERR_NGROK_SHIP_APP_REF_REQUIRED: A ship ref is 'ship/' followed by the app name - ngrok documentation

What does ERR_NGROK_SHIP_APP_REF_REQUIRED mean?

ngrok returns ERR_NGROK_SHIP_APP_REF_REQUIRED with this message:

A ship ref is 'ship/' followed by the app name.

Where can I get more help with ERR_NGROK_SHIP_APP_REF_REQUIRED?

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