Casinos typically have wagering requirements to prevent bonus abuse.
yeah, casinos typically put wagering requirements on their bonuses to prevent abuse.
And how we can verify that this online casino is licensed on the Telegram platform?
you can check their website playgram.io, if you check the very bottom of the webpage you'll see a Curacao license icon and if you click it it will lead you to a page showing that their website is licensed and verified.

Rewards in real money. No wagering requirements to lock your funds
I need clarification on this, but I assume this is only for a deposit that has no bonus. it would be nice if you could explain it more in detail so people won't misinterpret what it means.