Welcome to the Community, @Waldo313.

I'd be glad to help you add DBA and hide the parent company name in QuickBooks Online (QBO).

We can add this feature by adding a new location in QBO. Here's how to do it.

1. Go to Settings ⚙, then choose Account and Settings.
2. Tap Advanced.
3. In the Categories section, hit the Edit pencil icon.
4. Tap or turn on Track location
5. Hit Save, then Done.
    

Here's how to create a location:

1. Go to Settings , then click All Lists.
2. Choose Locations.
3. Hit New, then add the Name of the location you want to track. Then choose the option "This location has a different company name and communicating with customers" and enter the DBA.
4. Tap Save.

You can also visit this article on how to customize your invoice: Customize your Invoices, Estimates, and Sales Receipts in QuickBooks Online.

Also, you can import your own custom form style design in QuickBooks Online, please check this article: Import custom form styles for invoices or estimates in QuickBooks Online.

Stay in touch with me if you need further assistance or if you have any QuickBooks concerns by adding a comment below. I'll be happy to assist you. Have a great day.