How to refresh footer custom message when cart is updated?

Hi,

I have added in the footer custom message a shortcode to display the Points that a user will get if complete the order.
I have styled it and all looks good. Just I saw an issue when the cart is updated this part is not updated, I need to refresh the page to get the last value. Any way how this value can be updated as well?

Maybe js function that will update the value on an update of subtotal? Since this value depends on the subtotal value.