where can i find the logs of ionic and Loopback

i am building a project with Loopback and Ionic ,my ionic app and loopback server are not communicating , the api URL is fine.Even though iam not able to login using the api,thus i wanted to find the reasons for the not logging in ,i am trying to find the log file where everthing is recorded for the starting of server to ending of it .

I tried looking for log files