A Dubai shop writes its mobile as 050 123 4567. Strip the spaces and the leading 0, add the UAE country code, and the digits are 971501234567. With the message “Hello, I would like a quote.”, the link is:
https://wa.me/971501234567?text=Hello%2C%20I%20would%20like%20a%20quote.
The QR code on this page encodes that same address, so a camera and a tap do the same job as the link. The website snippet is an ordinary anchor pointing at it. Nothing in the example is stored. If the number you actually use is the one on a personal phone, every conversation still lives on that phone. The WhatsApp automation service is what moves those chats onto a shared inbox, with an assistant for the questions you answer ten times a day. Message fees for that setup are a different question, covered by the API cost calculator.