How to make an operator identification by number in the tg bot?

Question

Telephony

The person sends a number. In response, the number operator should be sent to him. How to implement it?

Answer 1

In Russia, the distribution of numbering capacity is handled by RosSvyaz. On their website, they publish a register of issued bands: https://rossvyaz.gov.ru/about/otkrytoe-pravitelstv...
In addition, there is MNP in Russia. Mobile subscribers can change the operator while keeping the number. This information is stored in the BDPN maintained by TsNIIS. You can check a specific number on their website, but there is no public access to the entire database. It is provided only to operators and some other organizations.
There are third-party paid API services that allow you to get an operator taking into account MNP, for example, from dadata.
If it is suitable for the task to determine the operator not very accurately, without taking into account MNP, then you can get by with free Rossvyaz data.
If it is important for the task to determine the region of the number, and not the operator, then the Rossvyaz data is more than enough, since MNP in Russia is possible only within the region.
If this is a training task, then you can learn how to do it on the data of Rossvyaz, and buy a few requests from a paid API (for a data it is 10 kopecks per number) for experiments. Both options will be useful to try to do it yourself.