ERR_NGROK_9011: Your legacy account is not authorized to run the agent on a custom network interface - ngrok documentation

What does ERR_NGROK_9011 mean?

ngrok returns ERR_NGROK_9011 with this message:

Your legacy account is not authorized to run the agent on a custom network interface.

Upgrade to a new plan at: https://dashboard.ngrok.com/billing/choose-a-plan

Where can I get more help with ERR_NGROK_9011?

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