Magento2 Expand Apply Coupon Code on Luma Checkout page

on Magento 2.3 I have edited the Apply Coupon text box to be expanded by default which works on the view cart page. However when I go to the checkout page (I am using default Luma child theme) the Apply Discount code box is not expanded by default like it is on the view cart page.

What is the path to the file that controls this on the actual checkout page?