Now this is a first.
Binance as much as know is an exchange and doesn't run a Casino and if they did it should have been promoted in their exchange or X handle.
It's likely a scam, hopefully you didn't loss anything .
Once you see a site or link with a popular platform name, make sure you engage in proper research before even clicking or inputing any data or possible.
It's likely a Scam.
Come to think of it, Binance is a big name online this days, people can easily hire that name and add it to their platform to attract people especially scammers, they can even design a page that looks identical to binance exchange so that newbies can feel at ease but I bet the end goal is to hurt and steal from the newbies.
Any beginner coming online to find anything using an online search engine will likely end up on the wrong page, nowhere is safe online anymore, it is no more a place where you can just tell someone to visit without guidance, I am certain that they will end up in the wrong places.
What OP is describing sound like a short time Binance business partnership to drive customers to the new casino using Binance log in information, I think I have seen something like this years ago but I doubt it still works today.