1. First of all upload the zip with the index.html on indiexpo, 
so the game will be automatically playable online.

2. Watch the Event at the end of every level.
You will see an IF CONDITION with a script:

window.IndiexpoAPI

This is to check if the user is logged to the indiexpo.net

3. add, in the IF CONDITION, a SCRIPT with this:

IndiexpoAPI.sendScore($gameVariables.value(02)).done(function(result) {});

where 02 is the variable used to count the points.

End! Easy and fast! :)

It's very good because a lot of players came back to check their scores and if they are still "the king" of the game.
So you can gain new players and views. :D

Bye and indiexpo forever!

Freank

p.s. not "to enable" the chart, you have to contact the indiexpo staff at info@indiexpo.net