By default the bfgminer application will not start with the API enabled as a security precaution. There are a number of resources available to help you understand how the API can be enabled.
Look for references to --api-listen, --api-allow and --api-network for a start.
Suggested Reading
https://github.com/luke-jr/bfgminer/blob/bfgminer/README.RPC
http://manpages.ubuntu.com/manpages/xenial/man1/bfgminer.1.html