To convert fiat currency to Ethereum, you have two options. The first option is you can change fiat to crypto on the gambling site you want to play on. Head over to the deposit option and choose convert. Input the currency you wish to convert and how much of it. Follow the rest of the steps and you will be home and dry. this however comes at a slight fee. The other option is to convert via a third party in your crypto wallet. it takes more time however.