Add Savings to Checkout - coding needed - Discounty App

[HelenVAC]

I have a sales campaign set up using the Discounty app, and I'm using their 'Savings on Cart' widget to show the savings at checkout, however it is not showing. I reached out to the Discounty team however they are unable to fix the issue as it requires some coding changes. I am using the Impulse theme. Can anyone help to have the savings shown at checkout? Example below from the Discounty widget on how it should display: