ERR_NGROK_SHIP_REGISTRY_CREDENTIAL_REFUSED: Registry HOST rejected the credential for user USERNAME - ngrok documentation

What does ERR_NGROK_SHIP_REGISTRY_CREDENTIAL_REFUSED mean?

ngrok returns ERR_NGROK_SHIP_REGISTRY_CREDENTIAL_REFUSED with this message:

Registry <HOST> rejected the credential for user <USERNAME>.

Where can I get more help with ERR_NGROK_SHIP_REGISTRY_CREDENTIAL_REFUSED?

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