You can't trust untill u test it. It's not for only telegram, it's for all the platform.
This is the first time I've seen this. Gambling with Telegram. It's actually a good idea. However, I am not sure how can we trust.
Most gambling games via telegram are really hard to trust as they can disappear anytime they want. Unless, they have good feedback from old-timers and they are already operating for so many years. If you want to try, maybe use their minimum amount of bet or use your extra cash that in case something goes wrong, it is not a burden for you.