POST request http://192.168.0.226:8081/trends 404 (Not Found)

i am trying to make separate pages for showing output in html and js. before it was showing in popup pages and ajax code was working fine but for separate pages only its showing POST http://192.168.0.226:8081/trends 404 (Not Found) error on /trends url. what reason behind that

You run a site that points to another server on a different port? (Apache/Nginx etc)? Running PHP or what? Is this an API?