Where do you put your google adwords conversion code?

I am seeing conversions in my adwords dashboard but seeing 0 conversions in Marketo. I have put the conversion code on the thank you page and I have tried 2 different locations. I have put it at the bottom of the page by using the HTML element as well as put it into the custom HEAD html under Landing page actions > update meta tags section.

Where do you put the conversion code?

Pat