The sub-product/service drop-down box for adding inventory is not showing up. Is there something in settings that I am missing?

That's right, @austin.aquina,

Sub-products were replaced by Categories. We use this to keep track of company sales and help organize reporting. If you have a sub-item, you will need to manually add them separately into QuickBooks to accurately account for your inventory quantity and cost.

Here are the steps:

1. Go to Sales, then Products and Services.
2. Tap New or Add a product or service.
3. Select an item type like for example. Inventory.
   
4. Add all the product details lik name, SKU, or category for what you're tracking, then hit Save and close.
   

See these guides for more information about adding products and services in QBO:

• Add inventory products in QuickBooks Online
• Add product and service items to QuickBooks Online
• Change product and service item types in QuickBooks Online

This forum is always open if you have other QuickBooks related concerns. I'm also here to assist you further. Just message or mention me in your posts. Have a safe week ahead!