Hi.
Remember that it is a debit card and you have to fill it before using it. You have 3 sources where you can add funds.
Account in Euro, for now only with other cards, BTC and ETH.
In the application you have an option to change the source between these 3.

There are no commission charged to top up your account, it's not possible to transfer to other bank cards you can only expend your balance.

There also an option to invest in crypto inside the app.

Glad to help you