Pass user token from my own wialon app to our hosting server

Hello,
i want to develop an web app tool for our customers
i am gonna to use js sdk and add this web app in apps section in wialon system to make the users open it like other apps( offline ,dashboard , echo driving)
so basically i need to pass  user token to my hosting server when user click on app icon from apps section
to use token in my js code as following :

var token = 'passed token from wialon when user clicked on app icon';
  session.loginToken(token, function(code) {
    console.log(code);
  });

so how can i do that?
can i get token with _GET in my php code or  another way?

thanks