ERR_NGROK_10103: Enter a valid domain name, like example.com, then request your domain again - ngrok documentation

What does ERR_NGROK_10103 mean?

ngrok returns ERR_NGROK_10103 with this message:

Enter a valid domain name, like example.com, then request your domain again.

Troubleshoot ERR_NGROK_10103 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_10103?

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