You use a the ajax object to request the url to get the string.
There may be a json plugin that lets you parse the text, but you can also just do it with javascipt via the browser object.
Basically you'd do something like:
Start of layout
--- ajax: request url "www.myurl.com/data/"
on ajax complete
--- browser: execute js "window.data=" & ajax.returnData
--- text: set text to browser.execjs("data.points")
Or at least very similar. I didn't bother to check if that's the correct names of stuff.
It uses window.data to make data a global js variable. This doesn't work in all exports.
So then in js you can access the global "data" variable to get at your values. Maybe a basic js tutorial could shed some light on this. Typos or errors would spit something to the browser console.
That json is an array of two dictionaries, so you could start with the above and create some events to create two dictionaries and populate them i suppose.