lws_get_internal_extensions() not found !!

[nethomas1968]

g++ -w -DLOG_TO_STDOUT=1 -oechoserver ../../Util.cpp ../../WebSocketServer.cpp echoServer.cpp -lwebsockets
../../WebSocketServer.cpp: In constructor ‘WebSocketServer::WebSocketServer(int, std::string, const string&)’:
../../WebSocketServer.cpp:99:23: error: ‘lws_get_internal_extensions’ was not declared in this scope
99 | info.extensions = lws_get_internal_extensions( );
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~
make: *** [Makefile:2: hellomake] Error 1