Where could I find the location box for bill payment transactions?

The location box in the Bill payment isn't available in QuickBooks Online (QBO), Czarina. I'll explain it further. 

We can enter the Location field for Bill if you are referring to location tracking. Otherwise, we don't have this option to input in the Bill payment page. As a workaround, we can enter the location of the payment in the Memo field when recording the Bill payment.

Here's how: 

1. Create a Bill, then Save and close.
2. After this, go to the Search bar at the top of the screen and select the Bill created beside RECENT TRANSACTIONS. 
3. On the Bill Payment page, click Mark as paid. 
4. At the bottom part under Memo, you can enter the information (Example: Location) in the box. 

Additionally, you can refer to this article for detailed guide if you want to track your transaction by class in QBO. 

Should you need additional assistance with managing your bill payment, I'd be glad to assist. Have a great day ahead of you.