ERR_NGROK_6609: Swapping administrators is not supported on accounts with RBAC enabled - ngrok documentation

What does ERR_NGROK_6609 mean?

ngrok returns ERR_NGROK_6609 with this message:

Swapping administrators is not supported on accounts with RBAC enabled.

Where can I get more help with ERR_NGROK_6609?

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