ERR_NGROK_319: You must reserve a custom hostname for your account before it can be used to create endpoints - ngrok documentation

What does ERR_NGROK_319 mean?

ngrok returns ERR_NGROK_319 with this message:

You must reserve a custom hostname for your account before it can be used to create endpoints.
Failed to create an endpoint with the domain <DOMAIN> for the account <ACCOUNT>'.

Reserve this name on your dashboard: https://dashboard.ngrok.com/domains/new

Troubleshoot ERR_NGROK_319 with your AI agent. Connect it to the ngrok MCP server, then ask what caused the error and how to fix it.

Where can I get more help with ERR_NGROK_319?

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