ERR_NGROK_1119: Cannot use binding address '-R ADDR:' with '-subdomain=SUBDOMAIN parameter - ngrok documentation

What does ERR_NGROK_1119 mean?

ngrok returns ERR_NGROK_1119 with this message:

Cannot use binding address '-R <ADDR>:' with '-subdomain=<SUBDOMAIN> parameter.
You may either specify binding address '-R <ADDR>:' or '-subdomain=<SUBDOMAIN> but not both.

Where can I get more help with ERR_NGROK_1119?

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