When it comes to Trustly, it is advisable to fund your account with the currency that is suitable for the country where the gambling platform is hosted without registration.
Check what currency is accepted for payment within the casino. It is specified in the Terms & Conditions, and it is usually tied to it all calculations. Consequently, in some cases, you may lose a little on currency conversions. Most often, such casinos use euros.
When it comes to cryptocurrencies, you can only fund your bitcoin account with bitcoins. There are plenty of exchanges online that regular exchange money for cryptocurrency.