How do I create a referral system?

Hello Constructor!

I have worked in a Taping game in Construct3, and now i want to make a referral system in in the game. First how can i get usernames from Telegram app because my game is in Telegram. After that the referral system which will include user can invite the other users and get some earning in the app. How it could be created?

Your response will highly be appreciated!

Thanks

https://www.construct.net/en/game-assets/addons/telegram-mini-apps-sdk-4263#:~:text=The%20Telegram%20Mini%20Apps%20SDK,with%20Telegram%20Mini%20Apps%20features. - This is available but it costs money.

And... with JavaScript anything is possible.