Should I suggest a combo when a WhatsApp customer orders one item?

Yes, once and politely, with a clear price. Suggest one add-on that goes with the dish, and accept a no without pushing.

• Suggest one thing that fits, such as a drink or a side, not a long list.
• Say the price of the add-on or combo so the customer can decide fast.
• Ask once. If the answer is no, thank them and carry on.
• Keep the offer simple. Two or three combos on your menu are enough.
• Note which add-ons sell, and keep those on the menu.