ERR_NGROK_SHIP_ENVIRONMENT_NAME_BAD_START_OR_END: Environment name NAME must not start or end with CHAR - ngrok documentation

What does ERR_NGROK_SHIP_ENVIRONMENT_NAME_BAD_START_OR_END mean?

ngrok returns ERR_NGROK_SHIP_ENVIRONMENT_NAME_BAD_START_OR_END with this message:

Environment name <NAME> must not start or end with <CHAR>.

Where can I get more help with ERR_NGROK_SHIP_ENVIRONMENT_NAME_BAD_START_OR_END?

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