You make payment or bet in Casino platform, the thing is that since we are experiencing high fees in bitcoin that doesn't mean that we most withdraw with bitcoin
It depends on the gambling site that you are using, there are some gambling sites that you must withdraw your coins compulsory using the network that you used for deposit. Stake is an example. Some gambling sites have exchange function, while some make you to withdraw in any other available network that they listed on their gambling platform. This remains to OP as he is the one that knows the gambling site he is using.
Well all the sites I know only withdraw to which currency you have. And those are all the big ones like the mentioned stake, but also sportsbet.io, nitro and so on.
Actually I have seen no site that lets u deposit A and withdraw B. Those must be fiat sites that only offer crypto to attract more players.
When you deposit btc, you play with btc. That means your winnings are also in btc -> can only be withdrawn in btc.
I gave up on btc with gambling a while ago. Almost all good sites offer altcoins as an alternative.
At stake for example you pay like 2$ in withdrawal fee (even still now) for btc withdrawals, while with LTC or XRP you pay 0.01$ or less. Easy decision.