[SR-Users] Kamailio error code 500 (6/SL)

Hi. I'm a newbie to Kamailio (so do not judge strictly). I have experience only with Asterisk and now I'm trying to configure Kamailio. With default config all is working as expected, but I'm trying to configure it from zero with minimal functions, but using parts from default config (those parts that I figured out). With my present config local calls are working great, but I can't make outbound calls. I've attached config file, sip-trace and debug log. I think there is a route loop somewhere but I can't figure out where. I would be grateful if you pointed out to me where exactly my mistake or just point me in the right direction =) Thanks in advance