Hello there, @Dvorak24.
You can either create a service item and add it as a line item in the purchase order. The other way is to create an expense account directly selecting in the Chart of Accounts. I can guide you on how to do it.
Here's how to create a service item:
On the other hand, you can follow the steps below in creating an expense account.
Lastly, I'd recommend consulting your accountant so you'd be guided appropriately in assigning a specific expense category to your transactions. Also, you'd be assisted on the best way to track your customs duties and taxes.
Swing by here if you have other questions about managing your expense transactions. I'm always here to help.