It's great to hear from you again. QuickBooks Online has many abilities and features depending on the version you're using. Don't worry. I can explain how you can enter the customer's name in your journal entry.
To assign a customer to an expense, follow these simple steps:
Go to + New.
Select Journal Entry.
When you fill in the information for your transaction, you'll see a column that is labelled NAME. If you click on the dropdown arrow in the box, you'll see your customer's names. Choose the one that you want to track the expense for.
After you've completed entering the transaction, click Save and close.