[SR-Users] push notification

Hello Everyone, Trying understand how push notification works based on Daniel example in 2014 Code in question: if(lua_runstring("do_push([[$hdr(X-VxTo)]], [[$tU]], [[$hdr(X-VxFrom)]], [[$fU]], [[$ci]])")<0) { send_reply("501", "No link to destination"); exit; } I understand how string should look like, but lua give this error ERROR: app_lua [app_lua_api.c:607]: app_lua_runstring(): lua loading state not initialized (call: do_push([[<null>]], [[4310]], [[<null>]], [[4311]], [[dd4cb9b2-bf21-1235-05b5-5254003e39bb]])) Is possible clarify how this part should work ? volga629