Step 1: Open the Existing Order
Go to the Order Details page or the Orders list.
Find and tap on the order you want to modify (e.g., Dine‑In · Order #000002).

Step 2: Click "+ Add Items"
Inside the order details screen, look for the +Add items button.

Step 3: Search or See Menu to Add Items
Search or click "See Menu" to add item
Then click "Confirm"
