Once you are done selecting your products and there is a "Apply Promocode" in cart where you can enter any coupon code or select that whichever is applicable. The amount will automatically be deducted from your total discounted price.
No, you cannot change your delivery address after your order is been placed. You can cancel the order within 5 mins. after order confirmation only. If you wish to cancel your order and place a new one.
Delivery slot cannot be changed once the order is placed. In case of an urgent requirement of change of the slot, please contact our Customer Support team and we will try our best to accommodate your request.