Hi there, @CO-ALU SX.

You can create a service exclusively for your vendor only or create a specific account to categorize the expenses properly. Here's how to create a service item:

1. Go to the Sales menu and select Products and services.
2. Select the New button and choose Service.
3. Enter the details and tick the box I purchase this product/service from a vendor.
4. Enter the Expense account.
5. Verify the details, select Save and close.

I've included this reference page for more information about managing products and services: Adding Products and Services, Customers, and Vendors to Lists.

Once done adding a service item, you can continue creating the expense transaction. You can refer to this article: Enter, edit, or delete expenses in QuickBooks Online.

You may consider checking out this article in case you want to track the sales or expenses in your business: Run reports in QuickBooks Online.

I'll be here if you have other questions about QuickBooks. Feel free to tag my name in the comment section to let me know. Take care.