Adding Google Ads Conversion Tracking Snippets

Hey everyone,

I'm trying to add a Google tracking event to record a conversion when a user either clicks the checkout button or the order confirmation page loads on my website. However, I'm having trouble getting the event actually to fire. It doesn't seem like you can add the HTML call to the checkout button to fire it on click, and for some reason, I can't get it to work on page load either. 

All of the documents or videos I've come across only go over linking Google Analytics or Tag Manager to your site, which I've already done. It's implementing specific tracking snippets that I'm having issues with.

Any help would be greatly appreciated!