How did you go with this @luisgfmartins?
Javascript can be added to a Bubble app in the page header (good for loading libraries), and in a HTML element. In the HTML element you can include dynamic values, when they change the HTML is “re-run” so that is a way to send data from Bubble to the javascript.
Getting data back to Bubble is a little trickier. The most straight forward at the moment is to have a text input element, have the javascript find it by its placeholder text, then alter its value and trigger its “change” event.
A simple example:
More complex example: