Talking from mobile to angular app that is communicating with the c# server via localhost

I have an angular client run on my laptop under Tomcat web server. I am accessing client from my mobile phone through my router public address (I have set the the NAT to forward all TCP packets to web server on my laptop). My client communicates with the c# controller using http://localhost:4000. Whenever I try to send a request from my mobile I get Unknown Error message. Could the problem be caused by the fact that I am using public address from my mobile, but the client is using localhost to communicate to c# controller?