Opening given file with browsersync

Question

Hello,

Is it possible to create a gulp task to watch and browser-sync for a given filename.  It seems that the default file opened is index.html.

I try using from a Terminal session,  a prompt asking  for the file to watch then opening the browser with that file. but not succeed.  I need to edit the url and add the file I want to watch like this for example (http://localhost:3000/test.html); test.html has to be inserted manually.

I'm using Emacs to edit file but really don't know how Emacs could pass the file I'm working on to that gulp task and reload the page on change. Thk