ERR_NGROK_SHIP_DOMAIN_ZONE_READ_UNAVAILABLE: We could not read ZONE at PROVIDER: REASON - ngrok documentation

What does ERR_NGROK_SHIP_DOMAIN_ZONE_READ_UNAVAILABLE mean?

ngrok returns ERR_NGROK_SHIP_DOMAIN_ZONE_READ_UNAVAILABLE with this message:

We could not read <ZONE> at <PROVIDER>: <REASON>

Where can I get more help with ERR_NGROK_SHIP_DOMAIN_ZONE_READ_UNAVAILABLE?

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