Count Up Animation w/ Storyline and JS variables

Hello everybody,

I'm working on an animated count up score for a quiz.

At the beginning of each question, I want my count up animation to start from 0 to its current score from the score added from the previous question.

I came across this thread to help with my project : https://community.articulate.com/discussions/articulate-storyline/creating-an-animated-count-up-number-javascript

And also came across this article : https://www.rabbitoreg.com/2016/11/05/javascript-storyline-two-way-communication-via-iframe/

I was able to make it work on its own, but I'm having a hard time to implement it within Storyline. I try to send my Storyline variable "currentScore" to the external HTML/JS file in a Web Object. So far, I tried many ways, it doesn't work

I hope you can help me to find the best solution for this.

Thank you!