[SR-Users] Jansson_get issues

Hi! I'm trying to get jannson_get working, but seems missing something. Example is quite simple, actually taken from wiki $var(result) = $null; jansson_get("pi", '{"mystr":"my input string", "count":9000, "mybool":true, "pi":3.14159}', $var(result)); When running this part of code getting ERROR: <core> [core/action.c:1139]: do_action(): runtime fixup failed for jansson_get param 3 ERROR: <core> [core/action.c:1518]: do_action(): run action error at: /etc/kamailio/kamailio.cfg:1030 Also tried with jannson_get(".pi", ...); jannson_get('/"pi"', ...); and a bit others. What am I missing? kamailio 5.2.3 Thanks!