Let's filter the column to display quantity (QTY) on the purchase order form, qb20.
Before that, let's make sure that the items table on expense and purchase forms is enabled:
Here's how:
- Go to the Gear icon, then select Account and settings.

- From the Expenses page, click the Bill and expenses, and toggle on the radio button in line with the Show Items table on expense and purchase forms.
- Hit Save, then Done.

Once enabled, let's customize your purchase order form. Here's how:
- Navigate to +New, then choose Purchase order.
- Click the Item details dropdown, and tap the tiny Gear icon.
- Tick the box for QTY to display this in the table.

You might also find this article helpful whenever you need to adjust an item's quantity to match what you actually have in stock: Adjust inventory quantity on hand in QuickBooks Online.
The Community page is always available if you have any other concerns.