It looks like you want to add a strikethrough to your compare at price on your theme. It also looks like your theme is a third-party theme called Pipeline created by Groupthought from our Theme Store. Third-party themes would be supported by the third-party theme developer and would be outside our scope of support. Have you tried to reach out to them?
If you haven’t, I recommend reaching out to them as they have created the theme and would know the best way to guide you with your compare at price on your store. You can get in touch through their form on their website here: https://groupthought.com/pages/contact or contact them through their email here: help@groupthought.com.