received a mail from shopify to change order confirmation code

[Naga-anniemos]

Hi

Recently we received a mail from Shopify asking to improvements to checkout and thank you page, in additional scripts area saying as below mentioned.

Replace "order.{anything}" with “checkout.order_id” in Additional Scripts and similarly update any downstream systems that rely on this data.

I tried to find additional scripts page through notifications section under order confirmation section but couldn't find the bit that says order.{anything}. All i found was --

orderdate16 = order.created_at 

<a href="{{ order_status_url }} == section 

<p><b>Billing address</b><br /> == section 

{% assign orderdate3 = order.created_at | date:'%s' | abs | plus:000000 | date:'%b %d, %Y' %} 

etc etc.

Where / how do i find which bit of the code to replace to checkout.order_id?

Any help would be appreciated. Please let me know what are the next steps forward.