When customer buy anything at checkout page there should be option of complete order or book order and when he click that the order is confirmed and we get a notification on mobile and on WhatsApp that we got order from so n so we can immediately message that person and send our QR Code and when they pay we can delivered it to them this is simple process and customer trust also build up in this as we will message them personally so they will not fear of ordering online . and its good for us also as we don't have to pay additional amount to razor pay or phone pay