Regardless whether true or not true about what he promises to do, what is the basis for trusting him with my money, a total stranger for that matter and of all platforms it's telegram which is a place widely known as a harbour for scammers.
There are gambling games that doesn't requires one to have knowledge and skills on it to be able to play, with some luck you good to having a win as chance permits. So making my bets myself and knowing where my money could probably go to is a much better. If I win I win, if I lose I lose. Better to lose a bet than having the feeling of been scammed.
You are mate, instead of trusting any gambling official via telegram, I think it's better to meet a guidance face to face, so that if there's any act of scam, you can know how deal with the person and where to look for the person but if it's on telegram, they can even delete all the previous chat and reset their user and the victim can not be able to identify whom they were chatting with. I don't think I can make the mistake of truth anyone with my money on telegram, considering the past experience I have had on that app.