ERR_NGROK_4013: You may not create a new account because you are already a member of the free account "ACCOUNT_NAME" - ngrok documentation

What does ERR_NGROK_4013 mean?

ngrok returns ERR_NGROK_4013 with this message:

You may not create a new account because you are already a member of the free account "<ACCOUNT_NAME>". Upgrade or delete that account first before creating a new account.

Where can I get more help with ERR_NGROK_4013?

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