Pixel purchase events

What are the variables i need to add to the code in order to see the value of purchases on my ads?

fb instructions:

Set up dynamic conversion values
If you have multiple values that you want to track (ex: you’re selling multiple items with different prices), you can make the value dynamic. We recommend asking your website developer to dynamically pass the value of the purchase in place of the 0.00 in the “value: 0.00” portion of the purchase event.

Purchase variables vary from site to site, so you’ll have to work with your developer on what your site’s variables are. Here are some common examples:

‘{{ total_price | money_without_currency }}’,‘currency’:‘USD’