Hi, I don't know if it can help you but I have seen the same service you are looking for on several sites.
One of them is ispoof.cc, the costs are a bit high but I can guarantee that it works (I tried on my burners).
If you are looking for sources, I invite you to commission the project to a developer.
It is not difficult to build a system like the one you requested.
As I have seen on GitHub it's full of fake repos that contain a readme file with Telegram contacts in them.
It seems to me very much a scam attempt, always pay close attention!
Please note: I have no relationship with the site.
If you are interested buy the "Trial" package first so you can check if it works as you need.