ERR_NGROK_235: The Format VAL is missing or is not a valid Event Destination Format

What does ERR_NGROK_235 mean?

ngrok returns ERR_NGROK_235 with this message:

The Format <VAL> is missing or is not a valid Event Destination Format. Supported formats are: <SUPPORTED>.

Troubleshoot ERR_NGROK_235 with your AI agent. Connect it to the ngrok MCP server, then ask what caused the error and how to fix it.

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