Mobile payments to an online store?

Question

Payment systems

Now I often see payments via phone on websites, it works like this, I write a mobile number, and I receive an SMS with payment details, I just answer, money is withdrawn from my mobile, the online store also receives a notification, because instantly my order is paid, I always pay with mts, but I suspect that other operators have the same thing.
In general, I like it and would like to add such a payment to my store, there is Yandex, Qiwi ... but this method is very useful, but I can’t find how it works, where the description of how to connect is not clear at all (
A yes, do not offer all kinds of inter-cash desks and robocash desks, no intermediaries are needed.

Answer 1

https://smscoin.com/ru/

Answer 2

The Yandex.Money button may be suitable: https://money.yandex.ru/embed/quickpay/shop.xml.