Explain how this service works in simple words REST API whatsAPP?

Question

API

There is a service that works, as I understand it, without the whatsapp API, because it’s not really possible to get it now, I tried it myself many times ....
on their website it says

The API-MESSENGER functionality is based on WhatsApp Web and is built on the principles of REST; to use it, you need a phone with an Internet connection and an installed WhatsApp application.

can someone explain to me on the fingers how it works for whatsapp?
1. I scan the QR code on their website, thus synchronizing my application with their service, how does it work?

Answer 1

They log into the Web version and send regular POST/GET requests to the page while they are logged in. Those. your API request is interpreted by the service and performs a series of actions as if it were a human.

Answer 2

The Messenger API is just a third party service from Whatsapp and works just like the rest of the APIs. Most of them work via whatsapp web, as you were told earlier. Tj is by scanning the qr code you conditionally upload the browser version of whatsapp to their servers. Now most of these apis are not official, which is not very cool if you are afraid of bans. But the official api is becoming more and more accessible. For example TextBack works officially.