Dropified automatically confirms the order in AliExpress by default. In other words, Dropified will click the "Place Order" button on the AliExpress Checkout page.
If you want the ordering process to stop on the Checkout page, you can tick the option in the Orders Queue settings to "Disable auto order confirmation at Checkout" then click "Save" button.
In order to get to the Orders Queue settings, you can simply start placing any order through Dropified, then close the new tab when it opens.
You'll see the Orders Queue window at the bottom of the page in Dropified.