Order Value And Order Id In Head Section Of Checkout

I'm trying to track sales conversions for google ads. Instructions from google say to add

to the head section after the global site tag.

I've got a meta.override.tpl where I can place the script. I was going to place it inside an IF statement because I only want it on the final step of checkout. Anyone done this before?

I can't seem to get the values for the $order_info.order_id and $order_info.total if I call them in the script. I also am not sure of what step I should condition the IF statement. What I have tried is:

{if ($config.current_url|fn_url) == 'https://domainname.com/checkout/'}
{literal}

{/literal}
{/if}

For the order landing page, you can create the following file in the My changes module

design/themes/responsive/templates/addons/my_changes/hooks/checkout/order_confirmation.post.tpl

Do not forget to clear cache

Thanks. Glad it will work without having to recode and push their script into the HEAD section.

Yes, it should work